First, you want to be really interested in a field NASA is interested in. This generally means you will be going to college for quite a while to get those high degrees, what’s called a Ph.D. or Doctorate, in math, engineering, or science. And NASA will want to see that you have applied that degree to real life applications: Aerospace engineers working towards better airplanes and space ships, chemists looking into how natural environments make good materials that can be duplicated, applied mathematics and physics figuring out cosmic problems.
You need to be in good health, though you can wear glasses now. No, they won’t be sending cancer patients or anyone with major genetic or health disorders into space anytime soon.
Finally, you will need to pass a great many physical and mental challenges and tests.
Lately, however, NASA has been foot forward in getting ready for Mars, knowing that the kids of today will be our colonists tomorrow. This means looking at those kids now, those who are getting into Space Camp, good swimmers, good photographers, and good with teamwork. They are also looking for good pilots.
So you kids know what to do now. Study hard, keep physically fit, and learn all you can. The future is yours.