Hero-image in default page and not clickable sites

Hello everyone,
i've been working with Grav for about a week now and have read through the first contents of the documentation.
However, I have a few questions about the design:

1. can I set up an hero-image or a header-image in a default page (template) in the Quark theme? For me it only works on a blog page so far and then unfortunately over the complete page.
   Unfortunately the documentation doesn't help me either.
   I just want a normal page with an hero-image and text/information below it, not a blog.
   When I put an image in the folder of the page it is displayed in the editor, but I can't set it as hero.
2. can I declare pages as not clickable in the navigation bar? Only the pages below should be selectable.

For information:
I use the current Grav version with standard plugins and them standard theme Quark, no skeleton.

If the question has already been answered, I apologize.
Thank you very much for your answers.
Christian

1. A default page doesn't include the hero functionality, but a modular page template would. You can add a hero modular page to the parent, then content or whatever you want in whatever order.
2. To make a page not visible in the navigation, you can set the visible flag to false in the frontmatter, or under the Advanced tab in the admin.

Thank you very much for your answer.
I will try it.