Find a local auto paint supply store, they'll carry foam pads and polish, typically
Meg's and 3M as they are oldest most established companies. For pads I like
Lake Country or Meg's as that's all I tried and they work equally well although I find the thicker Lake Country pads better to work with. A good polish for beginers is Meg's #80 and #83 as they are diminishing abbrasive so you can't over polish since the grit breaks down the more you use it. Always try and use the least abbrasive product that will do the job and you'll be OK.