However, beyond the astronaut component, there are many exciting opportunities at NASA including the jet propulsion laboratory.
There are opportunities in many different scientific fields: astrophysics, astrobiology, geophysics, chemistry, etc. Additionally, there are tons on opportunities for engineering, in particular aerospace engineering.
NASA is generally good about providing tours. You may want to see if you can go on a tour of the NASA in Houston and get a look at it. https://spacecenter.org/field-trips/