Ireegular shaped object collision detection

ok, i'm making an easy to make house, just to see if i can use collision, and its an RPG so you're supposed to walk around in it, but not walk through the walls xD
anyways, im not sure what else to tell you, i just need to know how i could stop at walls and such

oh, and if you want, you can use 'camera' instead of 'player' and 'CT'(collision test) instead of 'object
txs!