I have a new mac (purchased about 3 months ago). Somehow the downloads folder isn't pinned to the bottom anymore (I didn't delete the folder, I somehow moved it). I tried minimizing the folder and then dragging it to the right of the line but the other icons don't move. Does anybody know how to fix this?
You can just drag the folder from Finder.
The folders on the right side of Dock are called stacks, and you can also add them for other folders. See Mac Basics: Stacks.