Great read! I also think immersing yourself in the language outside class (ideally in a fun way) is an invaluable way to pick up more of it, e.g. music for listening or manga for reading.

I wouldn't call it a "mistake" per se as it could very well be a more cultural thing, but I believe it's important to not be held back by shyness too! If it's too daunting to practice with a teacher or native speaker, you can always do so with your fellow classmates -- you're all in the same boat.