And messing with stuff is exactly what you are doing .
If it has a spark at the right time , a combustable air:fuel mix at the right compression then it will fire if not run .
So you start with the easy things to check
Pull off the muffler and have a look at the exhaust port for obstructions & the bore for gouging .
Remove the carburettor, but leave the fuel lines attached, turn it sideways and blow air through it check for a a stream of fuel mist coming out
Do a compression test, ideally a small 2 stroke should go around 100 psi.
Unless you have very special small engine tester , the exact number will not be important because it will not be accurate but around 100 should run
Sub 100 and you are in worry territory and the further away the less chance it will work .
To play with these engines, a pressure & vacuum gauge is essential in fact it is the most essential tool .
For the lay person, a spark tester ( the red globe ones ) and a can of aerostart is the best you can do .
If it will not fire with a VERY SHORT shot of aerostart down the plug hole and a flash from the spark tester then it is essentially scrap metal