Board games allow a group of freshmen to gather around a table, compete with each other and have fun. You can either buy a new board game for such occasions, bring your favorite game from home or see if you can borrow a game from the college. Provide a few snacks to the contestants and be your best self -- don't cheat or start moaning if you lose.
You may like a sport but not be on the level of college teams' athletes. Don't let this stop you from finding fellow enthusiasts and having a quick game of football, basketball, baseball or any other sport you like. Check the availability of the college's facilities and if you are allowed to play in the common areas of the campus. Local parks and facilities are another option. Apart from meeting new students, such activities can also help you stay in shape.
Meet fellow freshmen while helping each other understand difficult parts of a lesson with study sessions. Don't see these sessions as a substitute to your long hours of studying but as an opportunity to discuss your queries and check if you have grasped the meaning of certain part. You can arrange study sessions at your dorm or at the campus' lawn during sunny days. Avoid the library; what you want is a lively session, not studying individually next to each other.
It is highly unlikely your college does not offer a variety of extracurricular activities, from fraternities to college newspapers and volunteer groups. However, if you don't find an extracurricular activity appealing to you, you can establish one yourself. For example, you can create a poetry club, arranging weekly meetings at your dorm or a common area, a fan club of a sports team or a performer, as well as a debate club, publicly discussing issues of local, national and international interest.