Should I start volunteering next semester or wait until summer/later?

Hello, Next semester I will be a 2nd semester sophomore. I will be taking orgo, 2 bio classes, intro anthro, and 8-9 hours of research a week. With other things I'm involved in, that's about 15-20 hours of ECs a week, which is the same as last semester. But, I have done 0 volunteering since coming to college. Should I try to start next semester? It's probably too late to get hospital volunteering, so it would probably be through one of the service clubs. My main concern is that my GPA... Should I start volunteering next semester or wait until summer/later?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums