Definitely a fun box! I overthought it during some steps for sure but kept at it and everything was straight forward as soon as I decided I was going to use my brain. Can say I learned a good bit from it which is awesome.
Initial Foothold: Its all over google, play with it a bit and see what it gives you
USER1: others have given good hints. however just enumerate and you will find what your looking for. probably the most painful part because of the “shell”
USER2 : This is the part I overthought hardcore. I missed one very important thing. But Played with some basic networking commands to see what was running and it stuck out.
ROOT : find a file, GTFO