Welcome to McMaster, and MacInsiders!
Sorry to hear you're having trouble meeting and networking with new people. Definitely check out the McMaster Facebook group for your class, so you can find others in your academic year.
Then look at joining a student club. There are lots of clubs you can join. It's the easiest way to meet new people. When I was at Mac, I met dozens of new friends through clubs and extra-curriculars.
Here are all the clubs you can join:
Also look into joining Maroons or SOCS. Great groups to be a part of.
Also look into volunteering for the CLAY and HORIZONS conferences run by the MSU.