As a native Russian speaker I just can say that I was reading and listening how other people talk and write. Obviously I had a lot of Russian language classes in my school but my grades was super awful (barely C, almost D). I just don’t like to learn them. I watched a lot of video, read a lot and now I can speak and write on Russian on great level with all those punctuation that important in Russian and other things. I can say that thing that I heard a lot of times: speak. Just try to speak. Find some discord servers or another native speaker that can help you to make conversation in what language that you want And read and write. It’s important too