Hi Sha, other than studying grammar and vocabulary from courses or books, I think the best way is to talk to as many people as you can and as often as you can.
Also, find something you like to talk about. One of the reasons people give up on language learning is that accumulating knowledge and vocabulary represents a chore, find something you like talking about, or someone you like talking to. For example, I like historical subjects, if someone talked to me about muslim society and places to see in the Middle East, I would pay closer attention to what this person would say and put more effort in understanding them and replying to what they say. I hope this helps you.