Customise Page Title
You can customise Content Builder header typography, font size etc. Go to Appearance > Customize > Header > Page Title
Header With Background Image
When you create a page or post. You can upload background image to header area. Look at featured image at the bottom right of edit page/post and upload image you want to display as header background image
Page Title using Content Builder
When you create a page. Check “Enable Content Builder” option. Select “Header” module and add it to content builder. It will open a popup with header’s options.
From header options. You can add sub title, content width, alignment etc. Once you finish customising, click “Update” and save changes.