What can stop my car from shaking? 2012 Impala on 20 inch rims

Sounds like a rim in the front is bent. Make sure there isn't any play in the steering components but as sounds like a bent rim if you can feel it at 20. Maybe you get lucky and just have a bulge in a tire

I got a 03 grand am its make a humming sound when im at 15 to 40 mph thin it stops

Go back to a reasonably sized wheel and tire.