I'm on a mac and I am having a hard time importing different file formats (AVI,MOV). Specifically, I'm learning the program and want to practice with my flip video that takes mp4.s. What is the best way to be able to use the mp4 files in PPCS4?
There may not be a best way. You'd be better off pairing your consumer camera with a consumer editor, or buying a more professional camera to pair with Premiere Pro.
Though you are talking about PrPro and not PE, down at the "gut" level, the two programs are not that far apart. Usually, what will work in PE will also work in PrPro - well, sometimes...