If you take a look around your community, you’ll find a lot of tech-related volunteer opportunities out there. Usually the library and senior centers need tech volunteers. You may not have to look any further than your own school, which may recruit volunteers for it’s help desk or to prepare tablets for incoming freshmen.
CS is a competitive major. You’re going to be up against candidates who do have related ECs and volunteer work. Carve out some time in the summer to “give back”.