Is it better to attend lower tier UCs or community college after graduating high school?

not enough info to offer much meaningful guidance. My recommendation would be - as long as you have completed the A-G courses with passing grades - apply to a couple of the UCs and several CSUs - including 2 non-impacted campuses (SF and East Bay perhaps) and your local campus. That way, there will be several doors open to you when the time comes. If you are accepted to all of them, you can still attend a CC if you want.

In the mean time, take campus tours of your the schools you are thinking of applying to.

good luck.