Deactiviate Activity and Friends


I want to make a site, where users can register and subscribe for courses (=Event Manager). Everything works fine, but I don´t need the activity-tab and the function to befriend in the plugin.

Is it possible to deactivate these things?
I will need these functions in the future.

I´m using the hypeUI-Theme - maybe it´s hidden in there? Because I deacivated nearly everything in the plugins!

Thanks a lot!