Well the catalog will be the same, you just need to open the catalog which you using in the Lightroom subscription version.
Lightroom catalog stores all the information about the edits that you have made on the images,keywords,label etc.
The default Lightroom catalog is stored:
Mac (user) /Pictures / Lightroom
Win (user) / My Pictures / Lightroom
If, however, you have made another catalog and have lost track of it, easiest way to find it is to select Lightroom > Catalog Settings (Mac) / Edit > Catalog Settings (Win) and click General. In the Information area, it displays the path to the currently open catalog. Click the “Show” button to reveal the catalog in the Finder (Mac) / Explorer (Win).
Also be aware you will lose several tools that are in the CC version such as Dehaze Slider, Dehaze Brush and a few others and all future enhancements until Lr7 comes out if you go with the standalone version.
Some users fail to understand that images are not "in" the Lightroom program. Your images are in folders on your hard drive, and the catalog is what Lightroom opens. The catalog keeps track of the location of your images as well as any adjustments you have made to them. When you switch from the creative cloud version to the standalone version, the only thing that changes is the program and how it is licensed. The standalone program will open the same catalog and will include all of the adjustments that you have made. Nothing will be different at the beginning. Just remember that you will lose some of the controls that are exclusive to the creative cloud version.
As others have suggested, you’ll be fine getting to your photos and adjustments of those photos.
Something else to consider is how much you’ve paid for LR CC, already. It might be better to wait to cancel your CC until LR 7 comes out or at least at the end of an annual CC subscription period, unless you’re at the very beginning and Adobe chooses not to charge you a hefty cancellation fee, which they could.