Take some time to read past posts on this forum about freshmen who are homesick/scared/lonely. The responses give great advice on how to be proactive in reaching out to those around you. Those first few weeks of school are prime time for making extra effort to smile, say hello, ask to sit with a stranger in the dining hall, etc. Everyone is new, unsure of themselves, and feeling a bit lost.
So, read up and make mental notes for your plan to take advantage of all the welcome events, orientation games and mixers, and propping your dorm room door open to meet others in your hall. The secret is that no one else has to know you are an introvert. You can put yourself out there greeting people, asking open ended questions, and passing out homemade goodies to your hall mates. No one has to know you will need to sit quietly in the library for a couple of hours to recharge afterwards.
You will have moments of feeling awkward, you will miss those childhood friends who really know you well, and you might be disappointed you don’t have a best friend after the first month. But hang in there. Your college will have so many students, there just has to be a tribe of folks that fit you. The folks you hang out with those first few weeks may introduce you to others, or bring you along to a dance or a club meeting, and there you may find the ones you click best with. But all acquaintances those first few weeks are good, even if you don’t click well. Just keep meeting new people, and you increase your chances of finding true friends.