How to get newly added page into navigation menu?

Hi,
(sorry if this is a very simple question)
Once I’ve added a new page how can I get it to appear in the navigation menu?
And how can I rearrange their order (which appears first etc.)
I’m revamping my site https://www.photoblog.ie/ and want to add home (https://www.photoblog.ie/home), galleries, most recent pages.
I’ve already added home page (need to fix the alignment) but it doesn’t appear in my navigation menu. Currenlty it only has ‘archive’ and ‘about’.

In my dashboard ‘pages’ section there’s nothing to
In WordPress.com sites the new pages are added to the navigation menu automatically.

Thanks,
Pa