When I click on the individual clips in order to watch, cut and edit them...they literally will not PLAY. When I hit the "play" arrow, it switches the "pause" image as if it's playing, but the screen stays frozen. It didn't matter whether I dragged them into the scene board, or just watched them in the media area.
Welcome to the forum.
Can you please give us much more detail, such as your platform (specs. will not hurt here), the details on the Source Footage, and your Project's Preset?
This ARTICLE will give you some direction.