Transferring?

Hi everyone,
I apologize if this is not posted in the proper place, as I’m new to this site.
I currently attend a private 4-year school and am looking to potentially transfer to a UC. I will be entering my sophomore year at said private school, but the cost of attendance is too high and I am already taking out loans to attend. UC tuition is much more manageable and will not require huge loans. Additionally, I will not be able to withdraw from this semester, as my tuition will not be refunded.
I understand that it is difficult, if not nearly impossible to transfer to a UC from a private school, so I was wondering if my proposed path would be feasible:
I looked at the IGETC paperwork and my previous coursework and AP credits will require that I take apprx. 5 more required classes at a CCC. So if I continue at my private school for this semester, then transfer to a CCC for the spring semester and I take the remaining classes for IGETC accreditation, will I be able to TAG or at least apply to a UC for next school year? My issue is in assessing whether my one semester at a CCC will allow me to TAG or apply as a CCC student. Additionally, the applications to the UCs are due while I am at the private school, so will they see me as a private school transfer and thus I will not have the IGETC certification?

Thank you so much for any advice you all have to offer.

So you need to be attending a California CC for Fall 2019 semester if you plan to file for TAG Fall 2020.

UCD has an additional requirement in that you need to be attending a CA CC during the previous Spring 2019 term prior to filing TAG.