Theme development

I installed one of the contributed themes and I like it, except for one tiny element, where I'd like to increase the font size. Is there a way of overriding a particular element style WITHOUT having to create a whole new subtheme?

I'm new to Drupal 8 and moved from Drupal 6, where this was easily achievable in themes I used by providing customising style elements in local.css file. In a multi-site hosting environment, I would:

Hello! I've created a very simple content type in d8 containing a multiple file upload with title text for each image. For this text, I've instructed the client to enter the url that they wish the image to link to -- in this way, I'm hoping to be able to associate each image with that url. (I can't create each image and link as a separate content type, because the client will be creating several of these galleries, and I'm using contextual filters to place them on various pages -- thus I need to keep each gallery's images in one place.)

So I created a region in my .info file that is called "banner". I will be using this region under the header to display a banner image depending on which page the user navigates to.

I have followed this tutorial

https://www.drupal.org/node/1497058

on how to create the block/view/and content (instead of a gallery, I just did it for 1 image) that will display in the banner block. Everything works well.

http://www.onegreenplanet.org

Hey Drupalers.

I feel like such a noob, but I just don't understand how to build a full website with Drupal 8.
I've been using it for about a week now, and I've been working on a theme.
I have some general questions.

Hi all,

I tried looking around but didn't seem to get any farther so i'm hoping I can get some answers to my question quicker this way. Any help would be appreciated.

This is from a already custom theme created that I am just trying to modify but in page.tpl.php there are variables like $page['main_nav'] and $page['more_footer']. Are these pages or blocks created in drupal? Like where do I access, example "Main_nav", so I can change the layout?

Thanks in advance.