I downloaded Lightroom 5 and after the trial period ended, I bought the Creative Cloud subscription. Now I have both Lightroom 5 and Lightroom CC on my computer. Picutres default to opening under LR5. I think I may have two catalogs and don't want that. Can I delete the LR5 software without messing with the catalog? Will LR CC find the catalog?
Yes, you can keep or uninstall your previous Lightroom version as you desire...
The catalog should have been migrated up to the new release when you first ran it. If not, you can find how to do it here;
Hope that helps!
yes you can Uninstall Lightroom 5. As you have installed the Lightroom CC, it has already upgraded the catalog and made a copy of it which is stored at the same location where the catalog of Lightroom 5 is stored.