Help - house gets so hot

My husband and I just bought a home here this past summer. It’s our first home so we haven’t experienced this before, coming from apartments. The house gets so hot when it’s warm outside. We had an HVAC team here in the summer once day when it was 90 outside, and they said the attic was 120 degrees. Even this weekend, the heat makes our son’s room so hot since his room is south facing and right by the attic door.

I am wondering if other people have experienced this. What have you done? Do you have vents in the attic. Dehumidifiers? Fans?

Trying to get ahead of it before it’s summer again.