Look at a D&D Character Sheet, or the character sheet for other table top role playing games. That is the kind of information you need. What can they do? Why do they do it? What is preventing them from doing it? Things like Birthdays and Favorite Foods are extra information that is useful for making smalltalk or timeline stuff, but not for the character itself.
You do, however, need to have some backstory for a character. It isn't great to have someone just plopped down into the world, unless the story you are writing is explicitly "This guy came into existence and was plopped down into the world". What kind of upbringing did they have? Were they rich or poor? Did they have a good connection with their parents or were they raised by nannies/droids/neighbors/the local priest? Did whatever powers they may or may not have impact how they were viewed by their family, or by their community? Are they highly educated, or do they just know what was taught to them by their parents?
The big thing, IMO, is that you start with the broad strokes and can expand it later, but for everything you expand you HAVE TO WRITE IT DOWN. The only thing worse than not having a bit of information when it becomes relevant, is giving contradictory information.