Transfering College? To UC schools?

Hi! I am currently a senior attending a high school in Colorado. So I’m very interested in University of California schools. However, my high school GPA isn’t very great (3.63 weighted) and my ACT isn’t outstanding (28).

I plan on attending CU-Boulder because… Well, it is a school I think I will like and the best shot right now for me. If I like Boulder and stay there, great. But if I don’t really like it, I want to go to a UC school (price not much of a concern).

So if I attend CU-Boulder and lets say throughout my freshmen year there I don’t like it, can I transfer as a sophomore?
Well actually, I know I can transfer, but what do colleges specifically look at? I heard they look at your high school grades and standardized testing, but do they look at that more or your grades freshmen year of college? Is it better to transfer to after freshmen year of college or after sophomore year of college?

UCs only really take transfers at the junior level (60 semester or 90 quarter credit units by the time of transfer). For junior level transfers, high school stuff is not required.

Also, UC financial aid does not cover the $25,000 additional out-of-state tuition.

UC’s give priority of in-state CCC transfers, then UC-UC or CSU-UC transfers and private school transfers and finally OOS transfers. Since you state money is not an issue, then expect to pay the $55K/year (projected to increase in 2 years). As stated by @ucbalumunus, UC’s only accept Junior level transfers (60 semester/90 quarter units) and they are particular on the courses which are UC transferable. I would wait and see where you are accepted before deciding to transfer even before you have begun Freshman year. You never know what will happen this Spring or two years from now.