how to access the data cache of an application

worked for some company using their own application to deliver parcels. never got paid and they claim that "i never worked" their application was used to track every single delivery I did.. i see it has about 35MB of userdata and cache storage that I cant access. How would I go about to accessing it? phone is not rooted and I have no experience with rooting but am willing to learn if it can help me find those files