I have just installed Lightroom CC. When I try and launch I get a window asking me to select a recent catalog to open with a note saying Lightroom Catalogs cannot be on network volumes or in read-only folder. Then I have a choice to choose a different catalog or create a new catalog. how do i resolve
If you have just installed Lightroom, and have never used it before, then you must "Create a new Catalog".
When you give the new catalog its name in a selected folder, it is as you state- "cannot be on network volumes or in read-only folder."
Once you have a Catalog, this will be the database that opens by default when you start Lightroom next time.