How did you code the multiplayer lobby? and multiplayer :| Is there anywhere we could talk like discord?
I used Unity and PUN2 (Photon Unity Networking 2) there are hundreds of great tutorials online.
Here's a great tut for getting started with PUN2
https://www.youtube.com/watch?v=evrth262vfs
Here's a great YouTube channel for getting started with Unity, although some of his older tuts use JS which is no longer supported ):