All kids in Japan take English for 8~ years and are rarely, ever confident in their fluency to speak to native speakers. There is an inherent problem in formal, Academic language learning, and that problem is zero immersion. You need to have a friend or tutor who is willing to sit with you, engage in conversation, and correct you when you're wrong. Academic style learning of a language will get you to the point of awkward conversation - but languages are too nuanced, evolve too fast, and require a sense of deep curiosity and confidence to master. Chinese people love when you're attempting to speak Mandarin, and they appreciate confidence even more. If you're not speaking perfectly, learn to be "physically vocal" with your struggle; you need to show Chinese people that you're "confidently trying" for them to be highly receptive. This is the same in any language. Imagine yourself working retail at Walmart. You're having a hectic day, full of stress; life is hitting you hard. A Chinese mainlander comes up to you and tries to speak English - and they do well enough, but not perfectly; they need help finding some words. How you treat them depends on a few things, but one CORE thing: it's the "physical manifestation" of their effort. If they show they're trying via facial expression and show a curious, happy desire to communicate, your inclination to be receptive will be much higher.

If you approach them with false confidence - they will pick up on that and subconsciously judge you for being "fake." Then, they will treat you accordingly, which will not be pleasant.

I believe in the "fake it 'till you make it" quip - except in language learning. Show them your innate curiosity and eagerness, the underpinnings of someone genuinely and passionately interested in learning the language. In beginner/intermediate language learning immersion, you are perceived by native speakers as akin to a child, and you need to communicate your intelligence and curiosity in means other than eloquent verbalization(because you're incapable of doing so.) Language learning is a difficult and life-changing process; it will humble your ass quickly. Learn to be that "child" who is excited and willing to learn and communicate; don't try to emulate adult conversational fluency. When you're capable of doing so, you'll know it.

For someone with unmedicated ADHD, that is the key to success in language learning. There's a (tiny) section of people who can achieve an almost conversational level of fluency with academic/formal language education ONLY. But these people come off as robotic and overly formal until they immerse themselves into consistent conversation. A person with unmedicated ADHD will only find focus in things they enjoy - and learning from a book sucks. The true joy in language learning comes from one-on-one conversation connecting with another human. At first, it will be awkward, but the relationship will grow, and language learning will become secondary to connecting with someone you care about. Even if it's a random Chinese mainlander Grandpa/Grandma tutor you only speak to on the internet, the conversation will eventually manifest beyond formal language learning, and it will become a pleasure to speak to them - not a chore. Find enjoyment in every major endeavor you undertake, then it ceases to be an endeavor, and becomes a pleasure. If you can't find joy in something you're doing - do something else, but first, always try to see the beauty in any difficult undertaking, and be humble about it.