put key in and start it.
3 months is not very long.
I started a truck that had been sitting for 15 years. tried the crank, it was free, put in battery, sniffed gas tank.. the gas was gone. it had turned into something that looked like burnt wood, (after I pulled the gas tank and cleaned it out I found that). I think it had been sitting alot longer,,, it only had 18,000 on the speedo.
poured some gas down the carb. fired up and I used a spray bottle to keep it running.
46 dodge pickup.
of course I checked that it had oil. but didn't change it as I was just seeing if it would run at all before I bought it. ran it for about 5 min.
then took it home, changed oil 3 times running it for 1 hour between oil changes.