I went to a community college starting around age 18-19, and I wasn’t there to socialize. I went to my classes each day and then left.
I don't know about your total experience in college/university, but like I was saying in another post, there was a formula (told to me) that about three to maybe four hours of additional time spent on course work and study for every one credit hour of class time.
It could vary from class to class, but you'll have group projects, where you'll have to get together with others to do some group work, and then you'll have lab time in some classes, you'll have library time, and then you'll have some people you'll get together with and share notes and work together on covering the subject matter. Sometimes you'll help someone else, and sometimes they'll help you (different people with different classes). You'll have down-time between classes, you'll also have (sometimes, and depending on how your courses are spread out) lunches and then dinners there. You may end up spending libary time, quite frequently) until 11 PM at night. I think the one at Oregon State went to midnight, if I remember correctly, and for good reason, too.
As far as "socializing" -- that would be part and parcel of the normal interaction you would have in doing those various things, for all your class work and class time. Any other "additional socializing" would be something, yet again, outside of your normal interactions with students during the many different university activities and classes.
For all the university work that I did, there was never a single time in any single quarter where I could ever just "go to class and leave after class" (and that was it). That would be impossible.
And depending on how many quarter hours you had, you could end up almost "living at the university" (even if you didn't). I remember one time I was taking about 24 quarter hours... hoo-boy! .... :-) You might as well "camp out" at the university, if that was the case.
First, I went to a community college full-time for two years. Then, I transferred those credits later to a university where I took classes sometimes full-time, sometimes part-time, for a few years. Like metmom, I always commuted; I never lived in a dorm. (I did visit dorms when I was young and had friends who lived in them.)
Back then, in CC, the students were all different ages, from young adult to older adult. Most of us were going to CC for an education; we were working people. It was a very different atmosphere from a university. At the university, I had an apartment off-campus, so I was there only to attend classes. The night courses especially had older adults who were serious about their education; a young boy or girl wouldn't have had a problem in those night classes at all.
At both the CC and the university, there were only a few classes where the students were expected to work on a project together. For most of the classes, all the work was independent.
My young son and I sat together in an economics course at the CC last year. The professor told us the CC students were working students who mostly came for class and left - the same type of students I remember at CC.
Also, community colleges offer many programs for people of all ages today - including programs for young children and teens.
My only concern with enrolling a 13 year-old into CC college-level courses would be the subject matter covered in the courses. There are professors who look for ways to cover topics like sexuality explicity. I remember those topics being covered in courses when I was in college. So, I personally wouldn't put a 13yo into English Comp, Literature, History, Statistics, or Biology. A mathematics or science course (other than Biology) might be more appropriate, IMHO. But, different parents see things differently.