How to move minecraft server?

So I'm going to my friends house today and I won't be able to host my personal server from my home computer. So I've decided to COPY the server into a pen drive. I plan to plug the pen drive into one of his computers and host there. Will this work? If so, by making progress in the server, will I need to move it and replace the original one due to making changes? Thanks!

Ps. If I may add, if you know, where are all the server saves inside the server folder? As in, if I destroy a block, where is that memory saved in the folder?

If you copy your entire server files to the pendrive, I can't see why it won't work. All that needs to be there are the files and everything should work flawlessly for you. You'll probably need to port forward at your friend's residence, unfortunately. Also, if you fish on Google, you'll find detailed answers for this entire question and the second part of the question.