I am having a problem starting a pull gas mower from snapper

My only suggestions are fresh gas and new or clean air filter.

Is the bail handle at the top of the handle bar operating easily? Follow the cable from the bail handle down to where it ends at the engine. Have someone operate the handle and see if the "brake" is activating. Check for a damaged blower housing (top cover of engine). Check to make sure the blade is not hung up in old built up grass under the deck. Check the oil level, you may have ran it low at the end of last season, causing it to seize up over the winter.