Chill...the only aspect of the CC version that is uploaded to the cloud are user specified Collection. You images and you application are still local (not in the "cloud").
Once you install LR CC you will be prompted to "upgrade your catalog". This will take all of your settings and metadata and include that in a LR CC catalog (your original catalog is preserved without being touched).
I just installed LR CC and am having trouble opening catalogs where I followed the instructions to upgrade. Just posted a question about it.
Discovered a problem when I went looking for some images that were not included in the most recent catalog. After opening up a couple of older ones and upgrading, I went back to the most recent and couldn't opening. Message says it is not writable. And also says it may be due to incorrect permissions. If you have any suggestions for this, I would love to hear them.