I have the good fortune to have a remote that is voice activated. Say 'captions', if its not on it turns on. Say captions again and it turns off. It rewards brevity. I've inadvertently activated that voice narration, and quickly got rid of it.
Sometimes, within a streaming show/movie, I need to arrow up and then to the right where there's an icon that enables subtitles in different languages. It's intuitive, it's trial and error.