The can crap is junk. It contains that stop leak stuff. If you can find cans without stop leak get those, and YES it does have compressor oil. You need to recover and pull a vaccum on the system for at least 15 minutes since the system has been open. Once done pulling vaccum it should hold 30lbs of vaccum for 5 minutes, if it doesn't you have a leak in the system.
I highly doubt you have a recovery station, but it's the best way to do this work. It will also inject the R134a and the compressor/PAG oil.
2k1 Oxford White Ford Ranger Edge 4.0L 4x4 ext. Cab Stepside 136k miles strong
245/75R16 Bridgestone Dueler Revo 2's, Bilstein Shocks, Optima Red Top, K&N Drop In Air Filter, 5000k HID's in headlights, 3000k HID's in fogs
"America is all about speed. Hot, nasty, bad-a$$ speed." - Eleanor Roosevelt