Learning English without anyone talking to you in standard English in your daily life is a challenging task. If you want to speak a standard English that can be understood by native speakers, you have to rise above the regional English of weird accent as everyone around you speaks that sort of English. この表現は自然ですか？

The first sentence is good. the next couple of sentences are also good, but it will sound even better if you say something like: "If you want to speak English that can be understood by native speakers, you have to rise above English with regional accents." the very last part i'm not sure I understand. do you mean that everyone speaks accented english around you or that they speak standard english?