Basic Page Editing
Understanding page organization is critical, and limits what you can do.
Each page is a vertical stack of full-width sections.
Each section may contain content items (text, images, documents, etc.) snapped horizontally to columns. Each section can be organized differently. There will be a small amount of whitespace between sections and.
Any piece of content directly below another in the same section gets "glued" to the one above. "Glued" content items have the same width and individual items cannot be given different widths. There will be a small amount of whitespace between glued content items.
Use the Insert tab in the edit sidebar on the right side of the window to insert different types of content.
Click to select a section below which you want to add something.
Click the content type in the sidebar to add it to the page.
Click the box that was added and drag it to the desired position.
Add text & images (Google help)
Tip: After resizing an image, click the Uncrop button to see the entire image.
When you click a content box on the page, a toolbar hovers at the top of the box with settings specific to that type of content.
e.g., clicking a text box shows text styles and fonts, clicking an image shows cropping options, etc.
Use the Pages tab in the edit sidebar on the right side of the window to drag pages to other locations. The website navigation menu directly reflects the organization of pages here. See how to hide pages from navigation.
The website navigation menu directly reflects the organization of pages in the sidebar viewable when editing the site.
You may have pages you do not wish to clutter up the menu. The only thing you can do is hide them.
Note the page still exists and can be viewed if its address is typed in or linked to.
In the editing sidebar, click the Pages tab.
Mouse over the page to hide and click the three dots.
Select Hide from navigation.
A major limitation of New Google Sites pages is that there are no tables. As noted above, content stacked in the same section has the same width. These two things taken together means that you cannot have images sized as desired in a column above or below text (or anything else of a different width). Sizing items in a column differently means putting them in different sections. Sections have space between them. Work around these limitations as best you can.
No Subpage List
You also cannot show a list of pages below a page. However, with the website menu set to be on the left (may need to press the three horizontal lines "hamburger" menu icon), the list of subpages shows for the page you're viewing.
No Recent Posts
There is no concept of a "page" of news posts or a way to show the most recent ones in a webpage.
Migrating is Messy
Migrating an old Classic Google Site to New Google Sites will be rough at best. Unfortunately, each page will require editing to make it look organized and not a mess. The more complicated the original page, the more work is needed on the new page. Anything using tables or columns will be a mess. New Google Sites is more limiting than the old website, so you will not be able to recreate everything.