Should I emphasize that I am first generation or will colleges generally know from my parent info?

There wasn’t a first generation box - was there? There was a box asking the highest schooling my parents had and I said some high school.
I’ve submitted my applications already and I’d definitely like to it to be known, but it’s not a big deal if it isn’t emphasized.

It’s a good question. I was helping my son’s friend with her application (immigrant parents) and we were wondering about that too. She didn’t want to write about what she feels are her parent’s struggles in her essay. Her GC says that the highest schooling box on the Common App is what the schools will look at but I don’t personally know this particular GC so I’m not taking that at face value. I suggested to her that she send an email to the admissions offices of her favorite colleges asking this directly but I don’t know if she’s done that.

Colleges will see your parents’ educational information and identify applicants as first-generation according to their definition (neither parent with education beyond high school, neither parent with any college degree, neither parent with a 4-year college degree, etc.).