You've asked two different questions! For the second question, just focus on standard English. I know we like to point out the differences between US and UK English, but the reality is that, in general, we understand each other perfectly well. It's still one language.
You could try to imitate what you hear in order to get the intonation, or you could get help from (or have a lesson with) a native English speaker. Some of the teachers here can help with your pronunciation and accent, which includes your intonation. You could get some very useful advice in a matter of minutes, instead of watching an hour or so of video and only guessing. :)