Editing a map in gmod then saving it as a bsp

Hey there! I got halo 3 foundry and sandtrap, and i am trying to find a way to edit the map (add warthogs ect.)…
But… my pc doesn’t handle hammer to well, and i dont know how to use hammer, so is there a way, i can just open the map in gmod
add the warthog ect. save as bsp
and then add to server and play?
is there a way using lua where i can just force spawn warthogs in certain areas when the server loads map?