First, all of this is premature since you’ve not taken any standardized test. Practice and study before you take your first test.
UCs are terrible for pre-meds because there are so any extraordinarily talented students there and so few med school places.
So, your choice will quickly be : do I want UCLA/UCB and find another future profession or do I really want to be a doctor and chose UCRiverside (currently the best for pre-meds).
What UofA?
If Arizona, what about ASU Barrett? Might your grandfather pay the reminder of any merit scholarship you get from ASU Barrett?
The best odds are at colleges that don’t weedout, will give you an individual pre-med adviser the moment you step on campus, and are collaborative/supportive (e.g., Bates, Macalester, Grinnell, Skidmore…to give you an idea of some you might not have heard of).