Trouble with layout of new site

I am in the first stages of setting up a new website in Twenty Sixteen and am having trouble getting it to look how I would like. (I maintain another site in WordPress using Genesis but it was set up by someone else so I am unfamiliar with setup.)

My site is tilliduff.one-name.net

1) I would like to reduce the size of the central block with the grey-green to show more background

2) I would prefer the menu across the top.

3) The whole page is too low on the screen – and how do I get rid of the large “Home”, the url of the page?
I ave looked in so many sets of instructions and cannot find what I need to know, so any help would be very welcome!