I get an offer for a CC based package of Photoshop and Lightroom.
I already have a standalone version of Lightroom5 installed. Do I have to download LR again or will my current version become part of the CC package?
What do I have to do to get a correctly installed and registered package?
Welcome to the community.
Please let us know if you only want to use Lightroom or other product like Photoshop as well or not.
As you already have standalone Lightroom5 installed on your computer, if you will subscribe to the CC package/ Photoshop Photography Plan then you will have to uninstall Lightroom5 standalone product and then re-install it from CC package apps.
To get the help for download and install please follow the below mentioned link:
Let us know if it helps,