How to create a briefcase to update certain files and folder to take home from work?

I am trying to figure out how to easily and quickly be able to create a briefcase type of folder where I can keep updating the folders and files that I work on at work, then updating my WD EasyStore 2TB external hard drive to take home and transfer the folder and file updates to my home pc. Then vise versa, updating the files and folders from home pc onto my EasyStore to update my folders and files at work.

If I can’t do this on EasyStore what should I get in order to do this. I tried copying the folders and files from work pc to easystore thinking if a file was already in easystore I would get a message which file did I want to keep. But that didn’t work and only created double folders and files. I undid that and am now trying to find another way.