Trouble installing and using nuplan_devkit

I am new to using python and it’s features. I am having trouble installing and opening the mini dataset in devkit. I have somehow installed the setup using the code given in the website and also copied the mini dataset to a folder in the nuplan dataset. My main issues are:I have also used miniconda3 to install all the packages as per instruction but how do I access those .db files? I want to see what kind of data is provided in the dataset to formulate for my research.
If anyone is interested to help me out I will provide my email ID, so that it saves lot of time. I would be really grateful for the help and support.
Thank you
Ankith Adam