Diagnosis
The most common culprit on a new unit is the engine safety features: the oil guard system or the fuel shut-off valve.
How to Fix It
Check the oil level first. The engine has a low-oil sensor. If oil is even slightly below the full mark on the dipstick, add oil until it's correct. Then ensure the fuel shut-off valve (on the fuel tank) is turned to the ON position.
If That Didn't Work
Verify the spark plug wire is firmly pushed onto the plug. It can come loose in shipping. Also, confirm you moved the engine choke to the CLOSED position for a cold start.
Heads Up
The factory carburetor may have preservative fuel that has evaporated. If it smells old, drain the tank and carburetor bowl (yellow screw on bottom of carb) and add fresh, ethanol-free gas if possible.