1996 Pontiac Grand Am

I start my car, then I have to put it in neutral, and rock it back and forth until it comes out of park, then I can drive it anywhere. Also when I put it in reverse, it will back up about a foot or two and then it acts like it goes back into park. I was wondering if its something in my linkage or if the parking ball is sticking, and what I should do to fix it thank you for any help you can offer