The March 15th one may have taken a week or two to spread around, so there is a good chance that you have 2019.0. You would go straight to 2019.2, skipping 2019.1, and your tools and extensions would be in the same place.
You should read through this topic first, in case you’re using one of the extensions that may not work with 2019.2:
https://forums.sketchup.com/t/sketchup-2019-2-release-extension-compatibility/99186/15