How to make NPC

Can somone please tell me how to make a npc and add it to the spawnmenu. I am wanting to make one for a shop script.

I knew someone was going to put that here. I have done my research and tried that post and one thing is is that it uses one file. I use threee (init, cl_init, shared). I am wanting someone to tell me how to make a standing npc. Thats all.

[editline]20th August 2017[/editline]

How do I make a npc spawnable and it just stands there?