Social icons + font size+tablets

Hi! How do I change the design of the social icons? www.inbe.se How can I change the font size on the header. The same goes for the headlines for Team and Testimonial. I have changed headlines to H4 and want all other headlines having the same size, how do I do that? I would like to use the contact icon for phone and email in my footer but have them placed side by side instead of under each other, how do I do that? I have also tried working with tablets but cannot get the border invisible - how do I do that?