You might try putting a spoonful of fuel in through the spark plug hole and trying to start it. Those small two strokes are sufficiently difficult to start without a dysfunctional choke and a questionable fuel tank cap. If fuel in the plughole results in it running briefly then stopping, you can focus on the fuel system and carburetor.
Some of those fuel tanks use a vented cap with a one-way vent, and some use a hose-type tank vent. What kind of cap you need depends on which system it has.
