If you can't find a GM willing to do this, you can always read existing PbP's.
While they won't teach you how to run a real-time game, they can give you a good idea of how to run games and how to use the existing rules*, as well as how to deal with stuff that's not mentioned in the rules.
* Note: No GM will know all the rules or apply them 100% correctly all of the time. But another thing you'll learn by reading the PbP's is that it's much, much better to just go with what rule the GM decided on the spot than start a rules argument, which invariable results in trouble, loss of play time and other players feeling awkward.