Theme development

Greetings to all Members!

I am continuing to explore Drupal. It is really powerful. But I can't find the right way to build a custom page.
I wan't to create a completely custom page with custom data.

Now I have following structure.

I've created the page--front.html.twig template file. And defined it like that

Hello,
Sorry if this is the wrong place for this post. Please move it if it is. I am not developing my own theme, I am attempting to use AdaptiveTheme.

I installed AdaptiveTheme to my subdomaine http://plans.sublimedreamvacations.com. It shows in the filetree in cPanel, but does not appear in the "Appearance" page in the Drupal interface. I contacted my webhost service and they suggested that I ask for help here.

CSS doesn't work. Please help!

When I drop a scald image in a field textarea and save it, the image is not displayed but the following code: [scald = 112: landing2 {"link": "", "linkTarget": ""}]

Would anyone know where the problem comes from?

Hi Folks,
i got a problem with my navigation.js library, for admin, anonym user it works perfectly fine but when i log in to editor acc it is missing (not loaded in the DOM)

it is defined in mytheme.libraries.yml

navigation:
  version: 8.x-1.0
  js:
    scripts/navigation.js: {}
  dependencies:
  - core/jquery
  - core/jquery.once

and attached in my menu template like this