@MrR3boot - Great box!!! Learned few things.
For hackers attempting this box , most of the hints are on this forum. I will just summarize for ready reference.
Initial foothold - enumerate the site. dirb, dirsearch are good tools to use. Pay attention to data you see after you register and logon to the site. Anything that has @ in it. Using this information try to register and get access to second console.
user - This was the most difficult part for me. Pay attention to data you input on console 1 and see how that data is rendered on console 2. Great learning!!
Root- pay attention to enumeration tools like linPEAS or linENUM and take hints from them. It is easy to miss. ( In my analysis, I missed the critical info initially).
Feel free to DM me or catch me on Discord channel, if you get stuck.