Hi & welcome to TSF.
OK - 1st off - if an engine has spark, fuel and compression - all at the correct time - it just has to start. So if your's won't - one of those must be missing.
So as a 1st suggestion - have you tried a little ether ("Easy start" / "Aerostart" spray etc) spray into the air intake - see if that gives you some indication that it is even trying to start. (Whilst tipping fuel into the plug hole works - you need to be very careful and only use a very small amount, otherwise you will hopelessly flood the combustion chamber at the engine wont start
If the ether in the air intake doesn't work - then, even though you say you have spark - maybe the plug is old / sick and is failing under compression - so unless you are confident that the plug is in good condition - then for a couple of $s - I would try a need (manufacturers spec) plug.
Lastly, is your fuel any good?? - is it relatively fresh?? - or has it been hanging around in the tank // tin for months & months??? Stale fuel can also be an issue with difficult starting - although I would expect at least a 1/2 hearted cough / splutter - even if it wont run
Given you have a mains voltage (120v) electric starter - then the engine should be turning over easily fast enough to get it to start - so if none of these suggestions get you going - we are going to have to look at more serious causes.
Let us know how you get on