Fueling outboard motor

New to boating this year used to go boating with my grandfather but nothing serious and recently inherited a boat with a 1984 Mercury 75hp 2-stroke motor. Just want to know what the fueling process is like for these motors. I saw in posts on here that regular gas station fuel is fine but ethanol free is priority if available. Is there a way to tell if the motor has oil injection or does the fuel need to be mixed with 50:1 two stroke oil in the fuel can.

Thanks for any help or general boating tips!