They always automatically add newly introduced features by default. You can however remove most of them if you don’t want them. Go to Apps & Features, select avast!, Modify and again Modify. Uncheck anything you don’t want and apply.

Some cannot be removed. They are visible in the menu, but they won’t bother you. You have to understand that you’re using FREE version and as such, it has some tradeoffs. Someone still has to pay development team and servers. That’s how they upsell it. It’s an one time annoyance. Not really a big issue considering you get superb protection for free. Certainly much less annoying than continuous popups quite frankly.