I have just touched little bit...
But this one was great start
https://wiki.alliedmods.net/Building_sourcemod
To build SM for practising and get AMBuild work.
Next build MM:S 1.11, you need solve few errors tough (I try use clang only)
At the end, there is not SM for CS2
But you can try load MM:S 1.12
https://forums.alliedmods.net/showpo...65&postcount=5
I have not much knowledge of MM:S plugins.