How to Add Header with Site Title

I’ve built my site pretty much fully, except that I notice there is nothing where my brand identity and brand type should appear. My brand mark is showing up fine, but I believe that might be my favicon.
I keep going in circles searching through the admin options for where the option exists to create this important part of the site.
I’m running Divi 2 as my theme.
Please help with detailed and clear instructions if you know how to do this, thanks!
P.S. If anyone is good with this particular theme, I can’t get the urls of my Twitter and G+ profiles to stick – keep hitting save and it says it’s saved but the fields go blank every time and the footer with the social icons just points back to the home page.