Theme development

I'm new to Drupal and am trying to do a tutorial I found on skillshare.com (Make Drupal 8 twig theme in 1.5 h + useful tips). I've installed Bootstrap Barrio and now am trying to install the sub-theme, Bootstrap 4/5 - Barrio SASS Starter Kit, as instructed on https://www.drupal.org/project/bootstrap_sass. 

On the theme´s folder:

Perhaps I have similar issue to this Drupal 9.2 template_preprocess_image hook not working.

When I put this code in myTheme.theme

I am very new to Drupal and i am building a custom theme. When I check my localhost from a logged out user i cant seem to see any pages. the node path is currect and i only get the title displayed. everything else is gone. I dont know what files i should share here or how to debug this issue.

I am using Paragraphs to add content and planning to use views later on for other content type.

Hi there, I've just installed IMCE to make links to image/files. But I've also seen people installing modules that allowes you, whenever you click on an element in the wysiwyg editor, that you can apply style to that specific element. Does anyone know which Module that is? And if it is stable for Drupal 8/9?

Hi there, I have a content-type called News. I've also made a custom view which I load on /news. The view should display teasers of content equal to News content type and with Search: Search Keywords (optional ). But sadly it's not working on the /news page. Does anyone know what I'm doing wrong with the settings to create that filter?

I do not like the way the Barrio theme displays form validation errors. It displays a little cloud containing the error message in plain text above the field with the error. I'd prefer it display text at the top of the form in red. I turned on the "Inline Form Errors" module but doesn't seem to work since the error messages are already inline.

Is this a Bootstrap 5 thing or is Barrio solely responsible for this?

I suppose an improvement would be to change the text color or the error message to red. Anyone know how to do this?