Blog Settings

Hi!

How do I add elements to the “Blog Settings” on the Highend WP Theme? I use the “Simple Blog” demo. Elements that are currently displayed on posts are:
1. Display Date
2. Display By Author
3. Display Categories
4. Display Comments Count

I’d like to add 1 more element to the Setting:
1. A text that says “This post may contain affilate links. Read the full disclosure here”. Also the text “here” needs to be an hyperlink to my disclosure page.

Is there a way to add any Custom CSS to the General Settings or modify any blog template?

I’ve attached screenshot (with red circle to indicate where I’d like to add the text).

Thank you.