The answer to this depends on how long you have been there. If you have been there 2 hours, you need to give it more time. If you have been there 2 days, you still need to give it more time. After 2 weeks, try and figure out what the problem is. Are you not getting along with your roommate? Are classes stressing you out? Do you feel like you don’t fit in? Are you homesick?
Think about what the problem is and how it could be fixed other than leaving? Can you change roommates? Can you change classes? Can you hang out with different people? Talk to your RA (Resident Assistant), your advisor, a friend or a counselor about how you feel.
If you are homesick, give yourself at least another 2 weeks. You can last anywhere for 2 weeks. You may find that after another 2 weeks you have made friends and getting into the pace of college life and are feeling much better. Remember, you worked very hard to get here – don’t be too quick to throw it all away!