With Sections you would need to increase the top/bottom padding of the Section to make it taller ( same applies to the Header Element).
If you want it to display full height then edit the Section > Settings > Custom Classes field add fullheight-section
You have a Header Element already assigned to the Front Page or the Entire site. Which contains your Google Analtyics script. You should remove this Header Element and place your GA script using a Hook Element instead.
There can only be one Header Element assigned to any give place. So fix the above then you should see your header element appear – make sure you give the Header Element some top and bottom padding as well.