I would take the plugs out and use an oil can to put about 1-2 tablespoons of Marvel Mystery Oil down each cylinder and crank over by hand. If it feels okay, I'd put the plugs back in and hook up the wires. Make sure the battery is good - maybe even hook up jumper cables to a nearby car if it's convenient.
But the main thing (for me) would be trying to get as much of the old gas out as I could. Not sure of the best way of getting it out of the lines and pump, but at minimum pull a lower screw on each float bowl to drain out any that's in there. Easier if you just have one carb.
Might want to consider rebuilding the carb(s). Then put some fresh gas in each bowl through the vent for an easier start. I found a clear ketchup-type squeeze bottle at Harbor Freight, I think, that I keep a small amount of gas in for this purpose.
After it's been driven a few miles or so to make sure all the old gas is gone, I'd change the fuel filter just in case.
Pat