I have spent weeks setting up LineageOs for my unsupported phone and I think I understood it.

• So /storage/emulated/0 is practically your home directory, all folders you can easily change are there.
• I don’t understand these memes, everything gets saved to /Downloads. The default file explorer is just crap. I use amaze
• the only really weird directory is the camera, it is saved in DCIM
• If you care about app specific app data go to /Android/data (for me its like the .config directory)