I hit my head a few years ago and there is a bald spot from where it got hit will it always be like that or is hair going to grow?

A few years...: Sounds like a scar from scalp damage a few years ago. If it has already been a few years and no hair grew from that area, it is very unlikely that hair will grow there. It likely will be one of the collection of little scars that a person accumulates over a lifetime of being human. Stuff happens. But, live wisely and wear a helmet, sports safety glasses, a mouthguard, gloves, etc..., when needed.