There's a lot of good info in this thread.

Please get some training. The NRA Basic Rifle and Basic Pistol classes are great places to start. If you care to PM me your ZIP code, I'd be glad to help you find an instructor.

I'd been shooting for 20 years when I took the Basic Pistol class (my wife wouldn't go unless I went with her) and I learned some good stuff. Now I'm a competitive shooter, an instructor and a league RSO and I'm still learning.