So your son is, or will be, 19 during this academic year?
What is he doing with himself now?
'Difficult time at college' covers a multitude of sins... as does the process by which he made his application and took up a degree place. Sometimes it is about needing to mature a bit, or having made bad decisions/mistakes that take time to recover from, sometimes it is about having disabilities identified and appropriately supported, sometimes it is about the institution and the particular staff. So understanding a bit more about that would be important.
It is not necessary to know what career you want. But it is necessary to understand what is involved in the courses being applied for and to be interested... excited... by them. He's already given up once at 6 weeks in. Again, understanding more about why is important - and there are of course big financial implications to consider because of that.
All of which, plus the added uncertainties and pressures associated with late or clearing applications, suggests that setting out from this point with the aim of returning to Higher Education in September 2025 may not be the most appropriate plan.
I would suggest
1) work and/or volunteering experience (paid work may be the priority because of giving up this academic year)
2) going to lots of open days and sitting in on as many subject talks as possible. Yes, there needs to be management of expectations but it shouldn't be all about 'what can he get into with the qualifications he has now'.
3) Looking at degrees with foundation years, depending on what his academic issues have been and why he gave up (rather than looking to transfer to a different course) [Possibly he was already on one of these but not well informed about what it involved?]
4) bear in mind that once he reaches 21 he will be classed as a mature student and admissions requirements can be more flexible. There's also less likely to be the baggage of what his peers did/are doing and where.
5) If there is any sense that his academic life has been affected by mental health issues and/or disabilities, getting diagnoses/treatment
6) Looking at ways to pursue his interests and study - short courses, making his own videos etc