Did you somehow turn on Easy Mode? https://www.samsung.com/au/support/...Zlx2_gtgcYq7E1oj6uF8-GKjnh0J8tzbXVAd6qZUVj6BD
Can you show us a screenshot of your homescreen?
When you say your apps have disappeared, do you mean just from the homescreen? Do you see them if you bring up the App Drawer?
Which Google apps are you trying to get rid of? Some Google apps are considered essential to the system and can't be uninstalled, while others can only be Disabled (in the Settings>Apps menu).
You bring up your App Drawer by swiping up on the homescreen. Review this: https://www.samsung.com/uk/support/mobile-devices/navigating-galaxy-smartphones/. Since it sounds like you're not very familiar with how Android devices work, it's worth looking through the other parts of that link.
You should be able to uninstall Thunderbird, but not Email and Messages (which are presumably Samsung's own stock apps). Facebook can probably be uninstalled, but if it was preinstalled by the carrier, sometimes they only let you Disable it.
When you bring up the App Drawer, long-press any of those apps. If you see an Uninstall option, then you can uninstall it. If you only see Disable, then you can't completely remove it from the device, but at least you can prevent it from opening or updating.
What about if you go to the system settings menu, then Apps? If you select Thunderbird there, what options do you see?
I have not answered your question yet because I have not yet determined the underlying issue based on the information you've given so far.
Have you already tried rebooting the phone? Can you confirm that you're logged into the phone with your primary Google account, and not some secondary account?
I opened the link and clicked it. It took me to "Access and organize the apps on your Galaxy phone", and I then clicked "Show all apps on your Home screen". It told me to go to Settings/Home screen. There is no Home Screen shown under Settings on my phone.I merged your recent posts together. Since you're a new member, the forum software tends to be less forgiving about things like posting several messages in close succession, since that can be seen with spammers.
There has been no radical redesign. Android has always had an App Drawer (which distinguished it from iOS, where every single app on the phone had to be on the homescreens). But many launchers do have an option to show every app on the homescreens (and therefore eliminate the App Drawer) -- here are the steps on a Samsung phone: https://www.samsung.com/us/support/answer/ANS10001342/. See what happens if you do that -- do all of your apps show up on the homescreen again?
You can see which accounts you're logged into by opening your system settings, then Accounts, then Manage Accounts.