Half-life 2 Mod

Now I know this isn’t the right place to put this but idk where else to put it, and facepunch has a great community so.

I am aiming to create a HL2 Mod, but don’t know where to start. Can someone please link me to some threads, vids, forums, etc. to help me out?

There are videos on how to create a source mod on youtube - just search it up