Oh SNAP!! We got an Okie or Texan on here "Yall". Another brother I mean. Welcome to the forum.
Carb going to, wait, gonna' need a boil clean job.
Definitely carb dirty or fuel tank with grass/dirt in it.
Needs one or 3 more cleanings. New engines don't do this.
Respect to you at 16, wanting to fix your mower. Props to you fine sir. Better than the other 99% of these jokers glued to their cell phone toys.
Use and I KNOW you have some of this. Some WD-40 ya'll, in the garage. Spray it around any spots where it could have a vacuum leak with the engine running. Any new smoke or lost revs, you have a leak.
I'm from Oklahoma. Ya'll is a virus around here LOL. Holler back......