Why are the menus broken?

When you create your first page, the menus in the header and footer are expanded because no menu has been selected yet

The header and footer are configured with a default menu in the theme. That menu ID isn't available in your HubSpot account so a placeholder for the menu structure is shown.

Once you edit the global header and global footer, the menu will function as expected.

Example showing the default menu in the header:

header-menu-expaneded-in-power-theme

Example showing the default menus in the footer:

footer-menu-expanded-power-theme

If you've configured your header and footer menus and the menu isn't visible, that is a different issue related to the advanced menu settings (your pages are drafts and not published, so they aren't visible).