So I was driving my car home from work and when I went to turn the car off, the key wouldn't turn. So after a lot of force, I got the key to turn back and get my key out. But now I can't turn the car on, the key can't turn. So my questions are is what could have suddenly caused this? And how much can I expect for parts and labor at a repair shop?

 

Could be the ignition switch has jammed or the key cylinder mechanism jammed. You won't know until some disassembly. Can't tell you about cost. Mine never goes to a shop.

 

I don't know how to do it and don't want to mess anything up. If I had someone who knew how to do it, I would like to learn, but I don't.

 

Click on the "how to" link in Shoebox's signature, and he has an instruction for replacing the lock cylinder.

http://shbox.com/ignsw/ign_switch_repl.html