First thing is pull the spark plug and perform a compression test. Testers are cheap online and vital to assessing top end health before going further. "Feel" isn't good enough. If it doesn't run but does have compression over 80 psi (which usually improves after running but may not, and 80 is WAY low but usually sufficient to start) then check for spark (leave plug out of cylinder and use a known good plug if the original plug shows no spark). Inspect fuel tank for rust and inspect carb externally. I just pull and clean them on garage sitters (there's plenty of videos on Youtube to use in conjunction with but NOT instead of the factory service manual).