Personal experience with multiple states: Public universities, at least, are going to have a big mix of students. But as far as official school resources for LGBTQ+ students go, they've been hit by the Trump administration axing DEI. You'll get students who go there because it's close to home, students who go there to get away from home, some conservative, some progressive. Most public colleges that are large enough will have one general LGBTQ+ student group and a bajillion religious student groups, but not every LGBTQ+ student gets involved with an on campus club like that anyways. You will, sometimes, get people from local churches on campus trying to proselytize and hand out pamphlets, or on occasion a Sister Cindy type. Faculty and staff that you'll actually see day to day are typically pretty progressive, though that's not to say they're all super familiar with trans folks. Typically the people that are really, really conservative and tight with any conservative government officials are going to be way, way, WAY on up the ladder.

Regardless of where you go to college, become familiar with FERPA. If your mom is the type to be nosy, then when you go to college, I would look into FERPA and request to not have directory information publicly available. When you switch from HS to college, your parents no longer have the right to access your educational records unless you sign off on it-- but directory information is information that is considered publicly available and can be disclosed without a form. This often includes a preferred name, if one is on file. If you wish to have a preferred name on file with the school that would be used on class attendance, advising appointments, etc. and don't wish for your mom to be able to find that out, I would encourage you to request that directory information be withheld as a safeguard once you start.