I’m not sure I’m understanding, are you asking how to add a page to your website? Just click on the pages section on your dashboard and then add the pages as need.
If you are trying to add the pages to your nav bars, you need to go to the menu section on your dashboard. Create a menu (on the right hand side), give it a name, then add the components you want on that menu (in this case, your pages). You add the components by selecting the pages you want in that particular menu and click the Add to Menu button (they are along the left hand side kinda). Then in Theme locations, select where you want the menu to appear. Top Nav is above your title, Bottom Nav is below your title, and Footer is at the bottom of the page.
Not sure if I’m following. If you are saying that all of those items that I am seeing when I go to your link are supposed to be pages (and not posts as it appears they are right now). Looks like when you created these items you created them as posts and not pages. Recreate them as pages, then do what I said above regarding menus.
Pages (at least how I use them), are typically more static, where posts are dynamic and continually getting added to.
You can actually put posts on your menus too, but if these are really pages and not posts I would recommend you redo them as such.