First person controller falling though the floor in my first level.

I'm a newbie still practicing and I'm doing a test level with some free assets from the store, specifically the modular street kit. I have an intersection and added some props and the level is still small, but big enough to be walkable. I added a first person controller and tried to play the level, but the character falls through the floor. I need some help solving this. Somebody please help me with this!

 

I solved the problem by adding some colliders. The solution was obvious, but since I'm a newbie I had some trouble finding it. I added a third person controller and everything works fine, but I'm not able to use the mouse to look around. Can somebody tell me how to enable it?

 

did you try Unity3d Wiki? They have some good free code with mouse