Firstly, you should schedule regular time with our teachers. The more you practice outside of class, the closer you'll get to your desired level. Secondly, outside of class, you should review and do the exercises. Reviewing will help you improve.
To make faster progress, you should also try to write your notes in English during class rather than Spanish. Ask your teacher as many questions as you can. There are no silly questions. This is one of the best ways to improve.
Don't forget about irregular verbs either. They are essential in English conjugation. A verb in the present won't be the same in the past. You'll be evaluated on this in the final test.
Every night, make a list of new vocabulary words, such as adjectives, verbs, and phrases, that you will later learn. If it's an expression, note the translation, as it's often not word for word but with an equivalent. This is a kind of personal lesson to further increase your knowledge.
Also, you should regularly work on the basics so you don't forget them: pronouns, grammar, conjugation tenses (knowing the difference between simple past and present perfect, for example), etc.
These tips will not only help you improve but also to quickly reach an intermediate level of English.