Okay, I’ve been driving myself crazy and have finally given into the immense knowledge of this forum. I see instances of people talking about accessing /tmp/ folder and doing things within. Which I very much would like to accomplish. However, I’ve gone in with samba / ftp / ssh / sftp or whatever else you want to call it.
I cannot for the life of me find where this elusive folder is. Any clarity would be awesomely appreciated! 
Samba is completely different from SSH. As far as I know there is no way to access /tmp via Samba.
Then that’s my mistake, I thought it was all encompassing. I’ve been following these instructions (http://www.lakka.tv/doc/Playlists/) to try and create a Saturn playlist. Ideally I’d also want to change the theme, dynamic backgrounds, and add cover art instead of screenshots.
I feel like if I could access this I’d have more of an idea of how it works. But here’s the thing, if this is only accessible via a command line of sorts, how do I tell what I already have and what I don’t? I’m a visual person and definitely don’t know any kind of scripting. Sorry for my ignorance. 
You can access the tmp folder through the CLI - Command Line Interface. Download Putty and connect through your IP. You will need another PC if your running the PC version login type cd /tmp you can type ls after for a list of directories within the tmp. The cheats folder is in there although I think there are issues with that.
None of what you are posting about involves accessing /tmp, which is the good news. Most can be accomplished by browsing to the samba shares.
I’m interested in help making the documentation clear, so if you want to try to get started with one of the projects you mentioned, myself or someone else here will surely be able to help you get through if you get stuck. We may even find ways to improve the documentation too.
@Bswin821 I only have a mac, so it looks like putty is out of the question for me. Thank you though for that suggestion.
@markwkidd Thank you for that offer. Well in my travels I’ve found Mountain Duck which seems to mount Lakka in the finder as SFTP which is pretty great.
Regarding playlists, I’ve already gone in and created bios files the way I assumed was correct. Which was copying the green text (located here http://www.lakka.tv/doc/BIOSes/) into a blank text file and saving it as the listed name.
Then using this link (http://www.lakka.tv/doc/Playlists/), I followed those instructions and created my own for Sega CD. However I cannot figure out where the cores are or how to link to them without the prior knowledge. But they seem to be located within /tmp/cores/. So I guess let’s start there, how else would I accomplish this?
Great, I’ve already found one thing that could be better in the docs! It seems like one more sentence to explain what a BIOS actually is would be helpful 
BIOS BIOS files are not files that you create – just like ROMs, a BIOS file is ‘dumped’ from the actual system that you are emulating. In other words, you need Sega CD BIOS files that were copied from a real Sega console at some point. BIOS files are distributed on the internet just like game ROMs, which unfortunately means that I can’t link you directly to a good one.
Sega CD Playlist If you haven’t seen this post about ROMs and playlists in Lakka, could I suggest that you take a look? Megathread: “Which ROMs work with Lakka?”
Most Sega CD ROM collections that use the ‘cue/bin’ format should automatically be added to a playlist by the playlist scanner. If you are intentionally using a set that is not supported by the playlist scanner then you’ll find the /tmp/cores path to use for the Sega CD emulator within that same Lakka ROMs thread.
But if you are using one of the Sega CD ROM collections that is supported by the internal playlist generator and they are not showing up in your scan, that could be a bug worth hearing more about.
Not 100% on that I’ve never done that. I am not as familiar with MAC but I know you can link files and directories through the Terminal I’ll look at some syntax and post on it this afternoon I’m not at home now
Samba support is built into OS X. I really don’t think it should be necessary to add extra software for SSH or sftp just to access the Lakka shares: https://support.apple.com/en-us/HT204445
From the Lakka docs: http://www.lakka.tv/doc/Accessing-Lakka-filesystem/
Windows, OS X, and most Linux distributions should be able to navigate directly to Lakka’s Samba share by entering \\lakka\ into their file browser.
Not sure if this will help or not but the /tmp/ folder is accessible from the terminal by typing cd/tmp/cores you can link files and directories by creating a symbolic link not sure if that’s your goal that would be ln -s file path directory (space) file destination. The tmp folder in the terminal may be hidden by default in which case ls -a would view it or should but again the \LAKKA\ at the explorer is prob the best option to just locate it. Also from the GUI under settings then directories/tmp/cores is listed
@markwkidd @Bswin821 Between the both of you I finally got it! Thank you guys so much. For some reason the cores folder now shows up after doing what @Bswin821 suggested.
Now, next order of business is to modify the icons and backgrounds. I’ve been trying to decipher these instructions. (https://github.com/libretro/Lakka/issues/368) I can’t figure out where /usr/share/retroarch-assets is located for the life of me. I did however find configfiles/retroarch/assests but there is nothing in that folder. Any suggestions for that?
To add to what ndrvtrl said about the “overlay” filesystem, the standard contents of the RetroArch assets folder can be browsed on the web to give you an idea what files are used and where they are located: https://github.com/libretro/retroarch-assets
Then all you need to do is put files that you are changing or adding into the folder at /storage/assets.
Finally, you have hit on an area where you might need sftp or SSH to complete the project because there is not a samba share for the Lakka /storage/assets folder yet. The good news is that /storage/assets will have its own Samba share to make this task easier whenever the next Lakka update is released.
From the hip the /usr/ may not be user it’s identifying the user soo with Lakka since the default is root that may not be needed also the system folders example: Nintendo - Super Nintendo Entertainment System need to be quoted “Nintendo - Super Nintendo Entertainment System” also the blank file usually means the path was wrong somewhere and if you used a command like nano it will create a new file if one does not exist. The directions in the link seem pretty straightforward I think it may be a matter of finding the right path
Well hours later and I’m still not getting it lol. First I found the new theme (systematic) within the link that @markwkidd gave and moved it on over to the appropriate sub folders, rebooted, nothing. But that’s okay, so I tried making my own home icon instead of the lakka icon. Put that in the appropriate folder and saved it as lakka.png, still nothing.
But the silver lining in all of this is that, as you said, hopefully they’ll make it samba accessible with the next update. If that’s the case there’s really no need to go crazy doing this. But nonetheless I still greatly appreciate all the replies.
Plus side, I figured out the Boxarts wooo! 
One last thing (I swear) that is really irking me is retro achievements. I’ve got the account linked and can see games I’ve played within the account when logging into retroachievements.org, but none of the achievements actually pop for anything I play when I definately achieve them. Currently I’m using all no intro roms, as recommended for lakka. Any ideas?
This is definitely going to happen in the next release, although I could not say at all when the release will be. I’m looking forward to it as well, and I plan to help add a small section to the documentation to help people customize and add XMB menu themes in Lakka.
I hope someone else can help you with RetroAchievements. You may wan to update the title of your thread or post a new one with a title reflecting that question.
You know, I was going to do that but I figured we were on a roll haha. Thanks for all your help