The sound you are hearing is probably just the piston moving up and down in the cylinder and the air moving through said engine as you spin the engine over while pedaling.
As far as not starting you just need to go to the basics. Air. Fuel. Spark. The first two need to not only be present but also in the right ratios. This means jetting being right and no air leaks present on the motor to cause a lean issue.
Spark is easy to check. Remove the plug from the engine and plug it back into the plug wire. Rest the plug against the cylinder head so the metal threads are touching and spin the rear wheel while the clutch lever is out so it spins the engine over (or take off the magneto side cover and spin the engine over with a drill with the clutch locked back). You should see spark. If not you found the cause so now you just need to track down the culprit
