I am a native Mandarin Chinese speaker, I took and passed a Mandarin Chinese certification exam because I wanted to teach Chinese. But aside from that, I think the best way to learn a language is to actually use it in practice with someone who is a native speaker. This way you know learn not just the formalism of the language, but all the nuance of the language. There's many idioms and pop culture phrases that doesn't translate well, the only way to learn those is to speak with a native speaker who is trained to teach the language. I'm also a friendly and social person, so it is easy for me to speak Chinese to you as if we're friends just hanging out. Which is a great way to perfect your Mandarin Chinese skills.