Clear communication isn't exactly a strong point.
Both versions are completely uncompatible!
There are multiple reasons but it is important for you that you'll never be able to open a project created with CP2019 in the new version. The good news is that you are able to continue using CP2019 (only version 11.8.2) along with the new version. If you want to have a responsive project (non-responsive is not available) in the new version you will have to create it completely from scratch. There is not even a way to import assets to the Project Library because the new version has no Library (yet, I hope).
'Conversion' process means starting from zero. And look out for all what is unavailable in the new version besides non-responsive projects: question pools, Video Demo, 360° slides, advanced actions, lot of system variables (like the Movie Control category), Master slides, object styles, shared actions. Many hidden and exposed system variables which could be used in JavaScript are also unavailable. It depends on the type of projects you are used to create, but keep both versions for the moment. When you install 11.8.2 (updating CP2019) it will be renamed to Captivate Classic and get a new icon. You can then install the new version to explore it.