Because you don't know the history of the motor I would recommend --
Change the impeller and take a spare one with gaskets.
Change the plugs and take a spare set.
Change the oil in the engine and lower end.
Spare starting rope.
Check the oil often in the begining for usage. I like to put the oil in one of those shampoo bottles that have the little flip open spouts. I think that engine only holds about a quart of oil total so add easy.