When someone shares a file with you, you may want to add it to your Drive so that you can organized it into a folder. Follow the steps below:
Click on the file (either highlighting it or right clicking). Find the "add to My Drive Icon" (It looks like the drive logo with a +, in this image it is in the top right corner.)
Once you click on it, a small menu will appear this is where you find the "organize" button.
Once you have clicked "organize" you can choose the folder in your Drive that you would like to put it into.