Can you tell if your engine has a head gasket ?
YES.... just get a good look (with good light) at where the head meets the cylinder.. there should be a thin but visible gap where the 2 meet if it has a gasket.
They are all just one piece metal (that I've seen) on 2 strokes. So you can just re-use them.
If you've been using 2 stroke oil and the bike is jetted right... there shouldn't be much carbon.