If you have installed the Visual Composer, Revolution Slider, Essential Grid, Showbiz Plugin you will probably face several activation messages.
Generally you can dismiss that message. The use of the premium plugins that came with this theme is allowed for this very theme and you are not obliged to activate a plugin other than the normal WP way.
If you decide to use one of those plugins in a different theme though you need to purchase a separate copy/license and then can activate the plugin.
Also if you like to have the option to automatically update the plugins (normally updates will be handled through theme updates) or need premium support from the plugin author you also can purchase a separate copy and need to activate the plugin.
Again, it is no obligation to purchase the plugin license and activate it for the use of this theme! It is optional if you need the above features. And please remember updating a not tested plugin could cause trouble with the theme, so please keep a backup copy of the old version just in case.