you can extract most of the well-known features such as MFCC, filter bank and so on .. using speechpy or librosa libraries. by using them, you can extract any features from *.wav file. the list of functions is here.you can choose the best of them depending on your need.
for example, you can try for MFCC by this code. also, it is very easy by speechpy ...
You can use a speech recognition software to recognize the beginning of your recording or a speech recognition API to code this.
If You want to implement this yourself, you can use a VAD algorithm to isolate the note at the beginning of the file, and then apply by a speech recognition method for classifying into a category.
With respect to ...