I can tell you one methods to improve your Chinese.
the vocabulary is the base of studying ,maybe you have listened many times.But i see your difficulty is that chinese characters have very complex way of written and tune,but do not worry a lot ,you can listen chinese videos and often pronounce by yourself.if you have very nice condition ,you could talk to some people who say chinese as native languageto talk about like how to write chinese characters.remember ,do not be shy!