Welcome,have a seat,this is what we do.
Remove prop,
Drain gear lube,fill with 100% synthetic marine gear lube tested with 10% water it passes.new seals/washers,
Remove lower unit, remove the water pump impeller, clean everything, remove all other bolts one at a time clean threads with wire brush grease threads well install back in same hole.
Drain engine oil,warm engine for five minutes first, drain from the bottom drain plug new washer on plug before you install plug remove oil filter,
Install new oil filter, fill with 100% synthetic marine engine oil .
Remove thermostat put in hot water watch it open around 120F and close.
Drain on motor fuel filter bowl, remove the filter,leave empty.till next season.
Remove the plugs, spray fogging oil for five seconds in each cylinder hold on to the straw so it doesn't shoot into the cylinder,turn flywheel the correct direction to move the oil around.
Clean all carbon off of the spark plug, threads,and body, grounding electrode.everywhere like new. Screw finger tight back into the cylinder.
Install a Yamaha mar-mini il fuel water separator if you don't have one. leave it empty fill with fresh gas first boating day.
Put your motor back together the first boating day of the season, OK a few days before. New impeller,gaskets.
I'm sure i forgot something but this is a good start.
Clean you fuel injectors, install a new filter on the inlet end of the filter, It's on you tube.
Adjust your valves cold
You could decarb your motor very first thing with 16 OZ of Seafom.with 32OZ fresh gas it's on you tube,before you change the engine oil.