Hey Bastiaan 
It really depends on what you want to hide. There is no a general way to do such a thing.
Some features can be disabled in the admin settings.
Some can be disabled through the plugins menu settings like the gamification or chat.
Some can be hidden with CSS like the suggested topics.
Some may be disabled through custom theme components or plugins.
If you have a specific list of elements that you want to hide, you can share it.