There are plenty of opportunities for math majors, but I’m no expert. My kid liked CS better than math. I don’t do chances threads, but from my POV the OP was a B student in high school and he’s still a B student. He’s got potential based on his scores. I’m pretty sure he’s capable of doing what’s required for a math major at the schools he’ll get into. I don’t think he’ll get any brownie points for being a math major vs any other major.
http://www.maa.org/careers
https://math.duke.edu/undergraduate/jobs