Yes, HUM + SOSC + CIV sounds like a workload and a half.
The first place to check is my.uchicago. That should display current enrollment for all courses.
Instructor consent for some classes hasn’t opened up yet, so bear that in mind if he can’t add a course with open spots right now - it may be available a week or so before classes start.
If his four-year plan has room for a few electives, Signature Courses are always a good option: https://college.uchicago.edu/academics/college-signature-courses.
These courses are taught by some of the College’s star professors, and most are interdiscplinary and accessible to nonmajors. I took Fred Donner’s Intro to the Middle East last spring and loved it. I have friends who’ve taken other courses and they all had a good experience. The format of these classes tends to be more experimental, which leads to the occasional misfire; one class, for instance, was taught by a couple of professors, and their lectures didn’t fit together as naturally as hoped. That seems to be a rare exception - most people like the classes.
He could pick a normal elective from the course catalog - there’s no shortage of good options.
Or he could take another Core class (one of the sciences, say).
@caymusjordan - Hum is required for the first year so he won’t be able to switch out of that. He’ll need to take at least two Hum in sequence.
Sosc. will have mostly first and second years; Civ was (is still?) known for attracting the older students but I just noticed that my daughter’s Civ. course is now closed after having a number of open slots earlier this summer so clearly there are first years taking Civ. Both sequences will be heavy on the reading and writing which is why it’s probably best just to take one of those along with Hum. Whichever he drops, he should be able to pick up for next year, since he’ll have registration priority over the incoming first years. If he chooses to keep Civ, he should just make sure that he completes at least a two-part sequence, since that is the Core requirement (six of Hum/Civ/Art with at least two Hum, two Civ. and one Art). Fulfilling Sosc. is simpler in that it’s a 3-part sequence that begins in the fall.
Edit/update: You actually don’t need to get on my.UChicago to search for classes or check enrollment. Just use this link which for some reason isn’t secure:
https://coursesearch.uchicago.edu/psc/prdguest/EMPLOYEE/HRMS/c/UC_STUDENT_RECORDS_FL.UC_CLASS_SEARCH_FL.GBL?&
Thank you @JBStillFlying - sounds like Civ might be the one he will drop and hopefully he can find something else of interest that is open!