Take your favorite show that you've already watched in English, and watch it again without subtitles. Watching something you're familiar with will help you fill in context based on what you remember.
Immersion learning is very hard and very frustrating the first time you try. Expect to only barely pick up on just bits and pieces, you'll start by recognizing vocab words but never the full meaning of a sentence. So watching a favorite show that you really like can help to make it at least a little bit less frustrating. Just trying to keep yourself from getting demoralized is the most important key.