In the 'Interface options' settings screen you can choose the interface you want to use. More on the different interfaces can be read on General Setting: Choose & setup interface.
Another thing you'll find on this page is the option to fill in an e-mail address where the contact form e-mails should go to. Click the plus button to fill in multiple e-mail addresses. Don't forget to save the page.
Next are the switches for different features you can turn on or off. Things like login, publication overview page, contact form, more info texts etc. Turn these on to see what they look like in the interface you chose.
If you have social media channels you want to show icons for in the interface you can fill in the URL's at the bottom of the page. If you have multiple languages you can fill in different URLs by switching tabs.