if you really sanded it really well with 2000 grit, you may get away with swirl remover. But a decent polishing compound costs like 5 bucks... soo.....
For pads, stick to foam, they are safer.
some rules ->
1) Dont mix compounds on the same pad
2) if it pad touches the ground, you're done with that pad, even if it doesnt look bad.
3) go slow. Not moving slow, slow on the buffer.
4) move around in steady up and down and side to side movements
5) dont be afraid to stop or keep going.
6) dont burn the paint! ;p