Hey There!
What kind of flying do you intend on doing?
If you want to fly in England for an Airline then you need to see if you can pass the Class 1 medical before going any further with flying for a living. For this you need to visit epaullette central down in Gatwick (The CAA) Where they poke and prod you to see if you fit the bill. This costs £411!
The standards are far lower for recreational flying and they tend to be more "user friendly" for American licences. But I would say checking out the medical side of things would be a good place to start if you're serious, as would having a go at flying a light aircraft. Even a 747 Skipper started on light aircraft!
Bill