It is possible to convert an R12 System to 134a, however some (not all) systems need some retrofitting. It would be best to consult your local manufacturer dealer about which parts may need to be changed. Some auto parts stores may also know. Keep in mind that the info is usually free, you're under no obligation to buy from any particular store.
Is r-22 Freon compatible with r-134a freon?
R 134a by Federal Regulations all cars have R-134a "freon" in the AC system since 1996 to present.
you need to put the freon in the low side, should be the smallest cap on the ac system
That is a reference to automotive freon type 134a
134A 134A 134A
Not unless you like the idea of destroying your AC system.