[[BT]Sweet]

As Craponnaruto said, you can't 'set' a spawnpoint in debug mode, you can only save one. Do as he has said, go to the position you want to place the spawn point, press T and then type "/save".

Then go to your GTA SA directory, and open the savedpositions.txd. Your saved position should be there.

Note: You should save the position on foot for a spawn point.