Ours is doing the same we needed to change the plug and the filter we got bad gas one time so we had to drain the fuel tank. If nothing seems to fix it call where ever you got it from and tell them it has a warrenty they need to replace it ,there might be a factory defect who knows.
Clean or fix the carburetor
Try pressing the primer right after you start it until it runs
If it's new they should be able to look up the records and service it under the warranty and even give you duplicates of the paperwork....
My mower starts and will run after a while it will start cutting out and then die, if yo wait it will restart but repeats. I replace the spark plug and cleaned the carb, any ideas?