If you are starting over - (you said you deleted your library) then you can ignore this questions which appears to be trying to open a .enl file that doesn’t have the necessary .DATA folder in the same location. If you don’t need that file, you would create a new one.
Going forward, you want to ensure that if you are moving or copying an endnote database, you move both the .enl file and the associated .DATA folder. They both need to be in the same folder (the .enl file can not be moved into the DATA folder, for example). openning a .enl file without an existing .DATA folder, will create a new empty .DATA folder. I would close it and create a new one in your user folder, and make sure endnote preferences are set to open that one, or open the most recently used (which is probably how it is set now and why it wants to open the older library).