Edit page (multisite)

Hello there,

this is aweseome theme which I will use for one my site under construction. Problem is that I am going to do multisite, so I install that type of WordPress. Now I can’t find out where to edit things like this: http://i61.tinypic.com/t5rarc.jpg

It’s written that I can change this things in Customizer, but there I can’t find where to change that text.

Every help is welcome.

Thanks.