Fresh gas and a sharp blade first.
Change the oil and fuel before you even pull the cord. Old gas goes bad over winter — it varnishes the carburetor and makes starting a nightmare. Dump it, put in fresh, and add stabilizer if you remember in fall.
Next: check the blade for chips or dullness. A sharp blade cuts clean, which means healthier grass and less work for the engine. While you’re down there, clean out the deck. Caked-on grass holds moisture and rusts everything.
Then check the air filter — replace if dirty, tap clean if it’s foam. Spark plug is usually fine but worth a look. If it’s fouled, swap it. Takes two minutes.
One last thing: make sure the safety bar and cable move freely. Cables corrode over the winter. Lube them if needed.
Your mower will start on the first pull this season.