Garry's base NPCs or NPC skeleton?

Since every Gmod NPC tutorial ever is out of date, I’m having a hard time making a simple npc. Can anyone tell me the directory of Garry’s HL2 NPCs or a simple NPC skeleton that’s up to date? I’m completely lost and I just really need a reference.

Are you looking for NextBot or an SNPC?

HL2 NPCs are coded in C++, there are no Lua sources for them.

I had not heard of NextBot before now. I think I can work off of this, thanks.