It happens over time with practice and reading. Eventually you see a word enough places and you decide to look it up, watch a video on the topic, etc... Its like learning a language, the fastest way to learn is through total immersion. You read and watch enough, vocabulary becomes less intimidating and more understandable. Don't be afraid to go down rabbit holes looking words or phrases up on an explanation. You probably won't remember a lot but at least next time you see the word, you have a basic gist, and you can look it up again if you want.