It depends on the lenght of your academy/college. Mine was through SFPD and was 7 months long. Nowadays, any degree helps in applying not neccessarily just a business one.
I do remember CHP being pretty stringent on eyesight. You might be able to ask your sister to confirm/deny that.
Your background sounds good so if you manage to get a POST before the age of 21 along with a degree, there will be plenty of depts that would be willing to pick you up. Keep in mind though, just because you obtain a POST some agencies will still put you through an academy. Also, you might have to maintain it as well if you get it way before the age of 21 or get hired.
Good Luck!
Be advised, I'm mean nasty and tired. I eat concertina wire and piss napalm and I could put a round through a fleas *** at 300 yards. So why don't you hump somebody else's leg mutt-face before I push yours in.