If you had your catalog folder located in a non-default location, Elements will rename it with a -1 (or other sequential number) suffix when you convert it via a version update. That version will still work with the version of Elements that created it (but you may have to use the Catalog Manager to find it in the old version.
The new converted catalog will be created in the default location. You can move the location if you want to in the Catalog Manager.
If you have no plans on using the older version of Elements, you can delete the old catalog, once you are assured that the new catalog is working with all components. However, catalogs are not backwards compatible. So, you will not be able to go back from the new catalog to an older version of Elements.