When one attempts to restart or shut down, if updates are available, it will give the options to restart|restart with update or shut down|shut down with update.
If it forced the update on you, it is likely that previously you didn't notice these options. You can only ignore the updates for a week.
There are other people here complaining about this. I wonder if MS did something out of the ordinary this time.
Those other AVG features are things that the ordinary user does not need. Anti-virus companies like AVG, Norton, and so many others compete with each other by adding features with important-sounding names. In reality, they take over the computer and restrict your access to files and websites.
At no cost to you, Defender provides spyware, anti-virus, and firewall protection. What else do you need?
Anti-virus programs can be difficult to remove. They, themselves, can act like viruses getting their hooks deep into Windows. Uninstalling the program can leave holes in the Windows software. The best way to remove them is to reinstall Windows.
Because the AVG program does interact with Windows at a low level, it is quite possible that AVG is the reason the update didn't go well.
I generally advise people to keep their systems as simple as possible. No unnecessary software.
Make regular and redundant backups of your documents, data files, photos, music, etc. The things you create are irreplaceable.
One day, another Windows disaster might force you to move on to another computer. If your backups are current, you'll be able to make the move.
Good luck.