Make the most of what you have and build on it
Make the most of what you have and build on it by focusing on using the English you already have and building on that.
"Recycling" what the student already knows is essential, it is the starting point in order to, then, start building up and out into the new - with teacher’s help: Your teacher will facilitate your learning by providing new challenge while reinforcing and correcting what has been learnt, and giving you, the student, the opportunity to actively speak, listen, read and write, facilitating it, not overwhelming the student.
Work on speaking and using what you already know, so you can actually communicate now. If you, the student, actually gets to speak in class, then the teacher will be able to provide corrections, and focus on the grammar points and idiomatic expressions that you need, when you need them: while you are trying to speak, trying to express yourself, trying to communicate, that is the right time to provide help, corrections and explanations.
Do you want to hear you teacher talk and talk, or do you want to speak and learn?