The two universities I lived in dorms at all had extensive activities planned during the week following move-in ("Frosh Week", "First Year Week", "Orientation Week"). Some were for that residence hall, others multiple halls, and still others the wide university community. Most were free. Often they involved free food and non-alcohol beverages (water, soda) to encourage participation
They were a great opportunity to meet people, at least to become familiar with some of the faces in your dorm and on campus. Also a great way to learn about the "traditions" of the institution.
That same week should also have events like "club fairs" where the various student clubs and organizations will have displays so students can learn more about them. Joining organizations is a good way to meet people with common interests.
The recreation center will often have free classes that week. Great way to try them out and see if they are something you want to continue doing. But also a good way to meet people.
One's major program or the college/school it is under will also often have activities. Great way to meet people in your major or similar programs. And the activities are usually pretty fun.
Even just getting out and going for a walk (safely) around campus can be a way to meet people as you encounter events happening. Also, it is a GREAT way to figure out where all your classes are going to be and how to get to them [nothing like trying to figure out how to get to an 8 am class... much better to have gone to the room the week before when you have all the time in the world
]. LIkewise where your major's and professors and advisor offices are. And the library [they may have orientation sessions that help you learn where stuff is and how to use the facility]. Health Centre [they may have some health information sessions]. Basically, take a campus map and go exploring.
While exploring can also be a good time to try the other cafeterias your meal plan lets you eat at. My 2 universities let us eat at any of the dorm cafeterias on campus. Some were better than others or had different kinds of selections
Exploring them became kind of fun, and it is great to know for when you have classes at the far end of campus that the cafe over there is pretty decent.
Also, I second the PP who said that being alone is not the same as lonely.
SW