The real "secret" is to study a little EVERY DAY. Make it a habit. And do anything that is interesting. Language study books can be boring. Studying boring things make it easier to  quit.

I recommend Duolingo, videos and youtube. (language learnign and anything interesting in english)

After a while you can try to read interesting books in English. If you are a beginner, then read something you have already read in your own language.

Could be as little as 10 minutes a day, but some days much more, however you want.

Consistency is the secret in achieving anything.