You can't wait for an invitation to life. Ask if you can come too, if you feel that it's a bigger party and not just a small get-together of just a few close friends. It's free to ask. You can also organise your own stuff. If you currently don't have anyone you would invite to a party, then I would focus on making better friendships first and then organising your own parties. Even if you don't have (m)any friends, you can go to student parties organised through your university or faculty, social events you can find on Meetup, or join a club or organised sports you enjoy and then try to make friends there.