Hi,
The link here doesn't seem to be working. Is there a link to the HTML site you are trying to replicate rather than your C5 build?

You will have to add in an autonav block when you go in to edit a new page unless you hardcode it in or add to page default but as you're new I will try to break it down.

When I am creating a new site I do a static HTML build first. Then I use that as a basis for the default.php, left-sidebar.php, etc etc.

My home usually looks a little different in terms of layout to the rest of the site so for example, the one I'm working on at the moment has an image slider on the home page at the top under the autonav with a full width area underneath holding the home page info.

The other pages in the site don't have this, they just have a narrow band running horizontally with the page title in it. and they have a 2 column layout for the rest of the page.

So in my theme folder I have default.php and right-sidebar.php - two files which I have created. I also have a folder called "elements" and this contains 3 more files I have created: home-header.php (containing the area for the image slider), header.php (no image slider - just the band containing the page title), and footer.php

My home page is based on default.php and that php file calls in the home-header file. The other pages are based on right-sidebar.php
which calls in header.php.

Once you have built your page types, click on "Pages and Themes" in the dashboard and go to "Page Types".
Click on the Add Page Type button. Where it says name you can add a name to distinguish it from the default page type.
For Handle - if you called your new .php file "my-page.php" then you just need to enter my-page in there.
Select an icon - it you can create custom ones but just select one that looks closest to your page layout for now.
For the checkboxes I always click all on the first row and the first one on the second row.
Then click "Add page type"

You will then see your new page style in the list. Click on "Defaults" for that page. The page should appear with the toolbar at the top so you can edit it. Click Edit Page, and in the editable area where your Autonav needs to go and Add Block - select Autonav. Then exit edit mode and save your page updates!

Now whenever you create a new page and select that page type it will automatically have the autonav.

Hope that helps!
Cheers
Allison