Or Moscow, home of the Russian Legion also the current number one team in the world.You're young enough to start out, don't worry about that. But being realistic, it's unlikely you're going to make a living out of paintball - most players on pro teams either work in the industry or have a regular day job.
If you are 100% set on playing for a US pro team, staying in the UK for the next 4/5 years will not get you anywhere near ready for that. You should move to the USA now, and spend the next few years grinding it out getting noticed and hopefully picked up.
The two States offering the climate for all year round paintball are:-
1. California, specifially SoCal, so you can practice at SC Village or Hollywood Sports.
2. Florida, home to the current #1 team in the world, Tampa Bay Damage.
Either way, Jon is right. You need to be playing the very best players you can play against, and also surround yourself with decent people.