Best place to learn Standard RT is to fly in Europe, starting by the UK (yes..maybe avoiding Spain and France...their chauvinism prevents them to speak English to their fellow countrymen - although legal, that procedure prevents non native speakers to be aware of "local speaking" traffic) and let me tell you that I find the UK ATC very professional (they even go to the point of speaking slower and clearer (quite contrary to what we see in the US) when they know they are addressing a non-native pilot.
I would say that, generally speaking, most of the European ATC's and airline pilots use standard RT.