Reply To: Double space blog content, font size, etc

1. Are you using the Visual or Text editor? The Text editor will ignore double-spacing. For maximum control over the post editor and post content, check out this plugin:

https://wordpress.org/plugins/tinymce-advanced/

2. Use:

.entry-content p {
  font-size: 18px;
  line-height: 145%;
}

https://startupwp.com/topic/customizing-your-theme/

3-4. Can I get the URL for this page please?

5. Are you using the built-in social media buttons or a plugin like AddThis?