As far as I know, launch pad is gone.
While you are able to install third party substitutes on your device (as mentioned by leroydouglas), which are supposed to bring back launchpad, Apple now expects users to launch applications from the app overview and accompanying search field.
Launchpad and its organizing functionalities yet have unfortunately not been replaced by any other concept in macOS Tahoe.
I personally can only recommend opening your applications through spotlight search, as for me it's just the quickest system.
Have a good day, still.