So ...
Upon activation, go to Dashboard => Updates Options to access the plugin configuration page:
As you can see, the configuration page contains five different tabs.
The "Dashboard" tab will allow you to quickly turn on/off updates for Wordpress core files, plugins, themes, translations, etc. I'd recommend you to keep the default settings here.
The "Plugins" tab will allow you to individually enable/disable automatic updates for your plugins:
On the "Themes" tab you'll find a list with all the themes that are installed on your site. Simply select the "Allowed" or "Blocked" options for each theme:
The "Logs", "Advanced" and "Premium" tabs are very straightforward so I won't waste your time with these details ...
Instead, let's see another important question: how to rollback to a previous version of the theme/plugin after update (if something goes wrong)?