16" bar. 35-40cc. Husqvarna or Stihl. Buy a good one and never get another.
I have a Husqvarna 435. A perfect occasional use size saw. When I lived on six acres with trees and was cutting a lot more, including firewood, and taking down trees, I had a Husqvarna 55 rancher with an 18" bar. That's a lot more $$, and more saw than I need as a homeowner who now only cuts downed limbs, or prunes big trees.
Use tru-fuel. I go through a quart of tru-fuel in the saw every year or so. It sits unused for months at a time, but still starts. No carburetor issues. No problems with the saw. I've had it for ten years. I changed the plug once, about five years ago, but it really wasn't needed.
Get a couple spare chains, so any work can proceed even if you damage or dull a chain. Keep bar oil on hand.
Get proper safety gear. Kevlar chaps. Face shield. steel toed boots. You may never need them...I've yet to hit the chaps, boots, or helmet in 20+ years...but like safety glasses on the shooting range, I can't imagine operating without them.