Decision Tree help.

Hi everyone, 
    I am choosing predictive analytics as my elective units for my commerce degree, but it is very challenging for me. sorry if my Qs sound silly, but please helpppp !!!

So I was given a dataset. I did he preparation and all that (not sure if it is done the right way ) and I used DT to predict the model. but my decision Tree looks weird and does not make sense. I have attached the screenshots below. Could anyone tell me how to solve this problem and the reason behind ?

regards,

Celine