You don't need TAG to apply for admission. If your GPA is already high & you're confident, you don't really need TAG. TAG just guarantees admission as long as you met their requirements.
If you want TAG for UCI (Winter), I suggest you go to your CC's transfer next week & ask about it. It's not too late, as long as you get TAG before you submit your application for winter admission (July 31st deadline). If your CC is in the UCI area, a UCI counselor is most likely in touch with your transfer center. Go to:
UC Irvine - Office of Admissions and Relations with Schools to read more if you're interested. Their requirements are very doable in my opinion.
Same with UCSD but as of now, SD only does TAG for a handful of CC's in California. So check here:
University of California - Admissions to see if UCSD does TAG for your CC.