Charge your ignitor and see if that works, then, if it's still not working, try a new plug.

Make sure fuel is getting into the carb, you should be priming the carb upon first starting.

Make sure the air filter is clean and not caked with old fuel and dirt.

How old is your fuel? If it's old and hasn't been properly stored it could have gone bad.

These are just a few of the basic things you should do if you're having problems starting your engine. If, after you've tried all these sugegstions, it's still not working, then we're gonna need more info and discuss more advanced troubleshooting.