With the XT500, it's possible to easily get a spark when you test with the spark plug removed. However, with a spark plug in, and then using a second plug attached to the coil wire to check for spark, you may find that it is much harder to generate a spark. This is less of an issue with the SR500 which produces a spark much easier due to its electronic ignition, but I'd start there.
It would help if you said what your starting procedure was, and what carb you have.
A hot start is a whole 'nother animal. First, master the cold start, then we can move on to the hot start.
Obviously, a beginner should set up the white mark in the window before kicking.
I know this won't help any, but my SR500 came with a very expensive aftermarket Mikuni TM 36-68 pumper carb, and it starts like a dream. I've been all through the impossible to start dance with more than one XT500.