Well, I believe it won't be a big problem!
At least, I'm in a stage that I should to improve my vocabulary, listening, reading, writing and grammar skills at the moment.
I'll learn the little difference between English English and American English like spelling, things name, pronunciation when I have enough above skills.
My learning method is a completely self-study so let me know if you know better method.
Hopefully it won't costs a lot lol.