I’ve already been accepted to 2 universities and i have no time to do 12 hours of community service between school, work, and sports, and i was wondering if i quit would there be any repercussions?
No.
If you said on apps to other schools you have not heard back from yet that you are doing NHS, then you should do it. Or notify their admissions office of the change.
It will make no difference in any way. NHS is pretty meaningless since getting admitted is based on the same information u submit to colleges. Requirements differ across schools-there is little of note about it and it won’t be missed.