Super-powers are mostly arranged into power sets: themed groups of related Powers. Some of them are basic Powers, though, that don’t fall into a particular set. In any case, you can choose freely among all of them, as long as your character meets any particular power’s prerequisites.

Your character gets to pick four Powers per rank. If they focus them into a smaller number of Power Sets, they might even be able to pick a few more.

If you have more power picks than you want to use, you can use the extra picks to add to your character’s ability scores.

Powers are complex enough that they have a whole chapter dedicated to them. Go read Chapter 7 to learn all about them, and then fill out the Powers section of your character’s sheet when you’re done.