Most pharm techs are trained on the job...it isn't necessary to be certified. Thinking of the ones that work in the pharmacies closest to me....age isn't a factor either as they are all very young and I mean in their late teens/early twenties.
It isn't a really well paying job although since you're in CA....it would be necessary to pay a wage comparable to the area.
Here's some quick info.
Pharmacy Technicians
Good luck