rust repair
 

Hey everyone im in need of some rust repair help. This is for my moms 01 grand am. Its getting super close to winter and she has a few very very mirror bubbles starting in the paint. Want to get them before the salt does. Now it doesnt have to be perfect and i dont have a DA sander etc. Now my question is what grit sand paper should i start out with and end with. Nothing is through the metal at all. Just want to sand it, prime it and use a duplicolor but still looking presentable Any help would be great! Thanks