Theme development

Hello,

I am new to Drupal. I want to make some modifications to the bartik theme i am using D8 (like changing the logo position, changing the size of font in article titles, etc) i created a subtheme named it "mytheme" following the instruction i found here:

https://www.drupal.org/docs/8/theming-drupal-8/creating-a-drupal-8-sub-t...

So, first I created the mytheme.info.yml file containing:

I am trying to edit the colors and background of the current theme and can't seem to find how to do it. I am in the css files doing it through code, but that doesn't seem to be working. Any suggestions on how to do it? I'm not sure of the theme name, I think it may be a custom theme.

Hello everybody, hope ya'll are having a great day and I hope that you can help me or point me in the right direction.

I am using one of the Drupal's free themes. What I have to do is to create a new page called, let's say Service ( domain.com/service/ but the catch is that this page needs to have a different header and footer than the rest of the site.

I've been searching for information on how to do this quickly and easily and i couldn't find anything to help, or maybe i didn't searched properly.

Any help will be greatly appreciated!

Thank you all.

i made my own module to hide a boolean when its value is "0"
but something won't work

this is the code

function MYTHEME_node_view($node, $view_mode, $langcode) {
if($node->content['field_members_only']['#items']['0']['value']=="0") {
                      hide($node->content['field_members_only']); 
                    }
}

sorry for the newbie question

Is it possible to declare a twig function in a custom theme? This documentation page says you can do it in a module, but doesn't specify if it's possible in theme.

For more context, I'm trying to add a font-awesome icon in a menu link. I have a custom twig template ready for this menu, but {{ link(item.title, item.url) }} always escapes font-awesome markup.

I'm trying to use the SASS starter kit for the Bootstrap theme. I've followed the instructions here: http://drupal-bootstrap.org/api/bootstrap/docs%21Sub-Theming.md/group/su...
and here:
http://drupal-bootstrap.org/api/bootstrap/starterkits%21sass%21README.md...