English is the language of science, English is for acquiring good quality information - information about your health, business, hobbies and so on and so forth. Find information that you are interested in. Find the information in English (not bilingual sources), and then read/listen/watch and begin learning the words by using a dictionary. I wish there was a secret, but there isn't. If there is one thing that helps me remember just a little bit better, it is writing the words on paper or on a computer. I learned Japanese 35 years ago at the age of 25. There was no internet and very few resources. I used two textbooks, I used audio cassettes of a Japanese Course, and I went to a Beginner Japanese language school for 148 hours. All of that took about 1 year. And by the end of a year I was able to communicate and understand the words I had heard and used the most. And I continue learning new words, and forgetting words even after 35 years. If you are under 25 years old learn languages now, because age matters. I have studied Russian ( русский язык ) for 5 thousand hours in the last 5 years and I cannot communicate. Age definitely has an influence on learning a foreign language according to all of us with personal experience and not "scientific" "theoretical" data. Find information that you are interested in. Good luck and don't quit!

Hello, greatest way is know how and when to use this vocabulary. Then have conversations to exercise this vocabulary ;)