The foam pad is all you need.
The pad that came with your buffer is probably pretty
low quality-I'd get a good pad to start.
There are different grades of foam, heavy cutting, polishing, and
fine swirl removing. Basically all of them will fit into one of these
You won't need a cutting pad unless you're removing sanding scratches
from leveling out new paint. Even then, depending on how fine you
sand, a polishing foam will work fine. Usually above 2000 grit.
Meguiars makes some good foam pads and compounds to go with it.
I use their yellow polishing pad with their #2 compound on existing
finishes and new paint too. It does pretty good.
You'll have to experiment to see what works for you.
Everyone has different preferences, to many to list here.
Google the Meguiars products and see what might sound right for you.
There's a bunch and it does get confusing but it's not near as hard
as you think.
I bought some "System One X3" compound off of Ebay that claims to do
it all. I am impressed, it does a good job. That may be all you need
with a couple of different pads.
Just go slow, and keep it moveing.