I suggest you start by enriching your vocabularies, one of the most effective ways is using apps such as Tiny Cards by Duolingo or Memrise that will help you memorize many vocabularies. However, start from the things you like. For example, me, I like movies and books a lot. So I watch a lot of movies and read a lot of books. Every time I found new vocabularies that I didn't know, I would write them down on a book and every day I practiced making sentences with the vocabularies I know. Don't worry about the grammar because the first focus is to have many vocabularies.
The next step is to learn from the conversation you hear from movies, TV shows, or youtube videos, or even books you read. You will adjust yourself with all the sentence patterns.
Third, try to find native speakers or at least those who speak English very well that can be your partners in speaking English.
Just remember, the key to success is your committment.
I hope this helps.