I think there will need to be more information provided for someone to help you.

What device are you trying to do this with? Google Drive works with Android devices, iOS (Apple) devices, Windows devices, Chromebooks, Linux, OS X, etc.

The subject of your message says you are trying to upload a word document but in the text you are talking about Google Docs. Usually when people talk about word documents they are talking about Microsoft Word but Google has a competing app called Google Docs. So is it a Google Docs document or is it a Microsoft Word document that you're working with?

Where is the existing folder you are talking about? Is it a folder on the hard drive of your computer? Is it a folder on a USB drive? Is it another folder within Google Drive?

Just so you know, Google Drive is Google's cloud based storage system. It's like the hard drive on your computer but it is on Google's servers so you access it over the internet. They give you a piece of the storage space on their servers and you can store whatever you want there as long as you don't bump up against their storage limitations.