Make sure air filter is clear and clean. Buy a can of carb cleaner, remove air filter. Open choke and open throttle. Give a 2 second squirt of the carb cleaner into the mouth of the carb. Hold throttle open and start it.

Standard procedure for starting small two-strokes that have been in the shed all winter and are reluctant to start.

Brake cleaner works quite well if you can't find carb cleaner.