CI is the correct answer. The ppl at dreamingspanish have a great breakdown of why it works. Chinese is a bit tougher because its much harder to find CI content, especially for beginner, but I've made faster progress in both spanish and chinese than I have with any other method.

I tried all the other methods people suggested below for years (flash cards, audio courses, reading); none of them worked. You might memorize words, but you won't actually be able to understand someone speaking to you. I have a friend who has a duolingo 3+ years streak (meaning she uses it every day), and still can't understand a native speaker talking at a beginner level. If she'd have spent even 1% of that time doing comprehensible input she'd be much further along.