World Physics

I have made a simple town and am trying to make it where my test person can’t walk through the walls. Should I apply physics to him or the building or what? Does it even have anything to do with physics? Heres a .blend if anyone is interested.

http://www.freewebs.com/magic-gun-productions/3rdProjectWorld.blend

well first you should give the player object the ability to move with the logic bricks, then perhaps make it a physics object, and play around with the mass and such

oh ya, duh. I forgot I was making the camera move not the player. I will fix that then see what I can. Thanks.