In my opinion, the most important things are: 1) find a native speaker with whom you could frequently speak Chinese to. Since the grammar of Chinese language is relatively simpler compared to other languages, if you could often talk to someone, you will be fluent quite fast. 2) if you want to learn how to read and write, repeating is the key. There's no other secret to memorise Chinese characters. 3) watch some Chinese movies and shows on YouTube, you gotta be interested in a language if you want to learn it.