To watch television in English, you can say "I'm going to watch TV" or "I'm going to tune in to the TV." You can also say "I'm going to catch a show" or "I'm going to sit down and watch some TV." If you want to be more specific about what you are going to watch, you can say "I'm going to watch the news" or "I'm going to watch a movie." Alternatively, you can say "I'm going to turn on the television" or "I'm going to flip through the channels."
