Question on header and navigation

Hi,

mh new to wordpress and started my first page, it should fullfill different stuff on the one side i want to have an archieve for my artistic projects. On the other side i want to write articles and posts.

Here is the address: islandofopenprocess.net

i have child theme and css editor installed, now my questions:

since the theme update my menu has two rows, is there any way to get back to the old single lined one?

I have a layout with 2×3 circles how can i increase the space between the navigation (header?) and the site?

Thanks in advance

Best

Martin