I can only tell you what worked for me: it's input. Read. Start using any brute-force method to learn the basics, like the 100 most common words. Then start rea

I can only tell you what worked for me: it's input. Read. Start using any brute-force method to learn the basics, like the 100 most common words. Then start reading stories aimed at toddlers (or especially written for language learners, there are apps), and keep going to more complex input as you progress. Do not worry about grammar; you will learn it intuitively as you move from simple sentences to more complex blocks of text. Do not worry about learning word lists after you have the basics; learn words in the context of the text you're reading. (I have no qualifications besides being a self-taught English and Chinese speaker, so take my input for what it's worth.)