One thing that helps here is to include a list of your gear under your sig (see mine for example). Then other users can answer your questions better, knowing what version of Cubase etc you’re using. Just a tip.
Groove 3 -
The groove 3 videos are good. Let’s put it this way - I’ve been a Cubase user for donkeys years but upgraded having missed out on several versions. Now Steinberg versions are flash - showing off their great product and sometimes have expectations of the viewer. with Groove 3, particularly Mark Struthers, they’re somewhat simpler (he’s so typically English!!) but for me, they helped to ease me into the upgrades easily. I find them very useful.
Re the Hub - Steinberg Hub should be one of the options on the Cubase menus along the top of the screen. Gives you access to videos, shop & much more. Not sure if it’s on all versions of Cubase (elements for instance) hence my opening lines.
Hope that helps.
One final thought - Groove 3 Cubase Midi Explained is pretty poor unless you’re a real beginner to midi & music.