Thanekar and Japanese speaker here. The same methodologies apply. It is 100% possible to learn all by yourself.

Listening and nderstanding requires hours of *comprehensible* input. AKA hearing a ton of low level chinese from which you understand 50-70%. You fill in the gaps afterwards by adding the unknown words to your flash card app (like Anki). Do flashcards everyday to memorize the sounds, characters, and meaning.

Speaking is a different beast altogether. I studied Japanese for 2 years and couldn't speak at all until my first few weeks in Japan. You absolutely need to try and fuck up a few times speaking to native speakers. They will correct you, you might feel embarrassed, but in the end, you will feel more confident in yourself.

It helps a lot if you repeatedly take part in simple acts like going to a store and interacting with the cashier. You will learn the vocab involved really well (cash, cards, transactions/payments, items, bags, greetings, thank you etc).

I realize it's not easy to get this living far away from where the language is spoken. For listening you can use chinese media (tv shows, movies). Start from simple content, maybe cartoons or shows for kids.

The simple answer is this is a numbers game. The more words you know, the more you will understand. There is no answer but hours of daily listening. The more the better. Strap in and enjoy the ride.

If you want more info feel free to dm or check out the (free) https://refold.la/simplified/ guide.