What works for me when learning another language is to start with audio/video, plus the text. That is, read while you listen. Then listen again without the text and see how much you can follow. You'll find your listening skills build up. It's just practice, like any other skill.

It's really hard to understand the English accent but you can always practice. You're right, the best way is to watch english tv shows, English movies, anything that will make you familiarize with the English Accent. You can do it! :)

I am not sure which "English" you're referring to. Do you mean UK accent or US accent? As far as I know, both have different accent (but not much), but yes, you can learn those accent by watching movies, reading books or novels, or just listening English music in a daily basis.