Training the dataset after converting to Market1501 dataset

I used the detrac tools folder to convert the detrac dataset to market1501 format
Now i want to train it and the code in the cosine metric learning repo expects two folders i.e train and test if i am not wrong.
Can i just split the dataset into 75-25?
and also should i change the size of the images from 100*100 to something else?
Any help will be appreciated.