I never used java before. I'm on Minecraft 1.21 and with the help of #4466 I made baritone compatible with that version. The only issue is that I don't know how to compile it into an executable jar file so I can use it.
Thanks!

What IDE are you using? I just went through this as well. I was using Intellij. I had to pop out the Gradle menu, then under Tasks->unimined I double click remapJar. It compiles all the versions into a usable jar file located at (in the explorer) ->build->libs