I’ll let one of our chinese members handle the chinese question.
Those things are useful, but to be truly effective you need to repeat out loud and if possible, record what you said. Then compare it to what the instructor said – very carefully. Otherwise you may learn incorrect pronounciation.
Incorrect pronounciation may end up not letting anyone understand what you are saying, even though you know the words.
It’s really actually easy and fun to teach yourself that way, all it takes is your time.
These audio courses do work quite well, given you make very sure you are pronouncing correctly.
You’d be surprised how much you can learn, and anyone can do it.
US schools are about the most abominable places to encounter one’s first contact with a foreign language. 90+% of all people who try to learn there come away thinking they are not able to. Nuts!