The amount of time you'll spend with your unit will vary from school to school. At my school we had drill twice a week and PT once a week. I've heard of other schools with PT three times a week and drill once a week. On top of that, you can plan on having to spend a few more hours a week with them for stuff like platoon meetings, shoe shine classes, sailing classes, maybe some watch, a few fundatory social events, etc. I'd recommend contacting some of the NROTC units and asking their freshman advisor for specifics. In addition to the mandatory stuff, there might be other activities you could choose to be part of, such as sailing, drill team, maybe a marksmanship team.
I knew plenty of people who were active in NROTC, were engineering students, and were still active in other school activities like club sports, fraternities, and outside jobs. and they still had social lives outside all of that. don't worry, there'll be plenty of time to take that remedial typing class
