New user not finding the menus

There are TWO versions of "Lightroom": there is Lightroom Classic (available in the Photography Plan with 20GB of cloud storage), which stores images locally on your hard drive(s) and does have the various Modules that you've obviously seen in the videos. Then there is the app called simply Lightroom, which is also available with that 20GB Photography Plan, but is additionally available via the dedicated Lightroom-only Plan which comes with 1TB of cloud storage. Lightroom requires all images to be stored in the cloud (which is why it has a 1TB variant).

It sounds as though you've downloaded the Lightroom app, whereas you may have intended to use Lightroom Classic instead. Depending on which plan you have subscribed to, you may find you already have Lightroom Classic available to download, but if you subscribed to the Lightroom-only plan you should speak to Adobe's Customer Care to switch to the Photography Plan if that is what you want to use.