Hey man, welcome to the forums, a FPS is a big undertaking so I really wouldn't start there. Look at the pong stickie at the top of this area for a really basic idea of stuff, then try to make breakout or something along those lines.
Starting something too big will just make you give up and hate DB and then you'll never come back to it. Now i know you don't want to learn pong, but I did and now I'm making a space sidescrolling shootem up, you have to work up!
Well, I'm trying aren't I.....
When Life gives you lemons make orange juice. Then sit back and wonder how it was done.