Html,Css,Js,Botton and list elements

Hi,I have a question.
I want to make a button on my site, so that botton should runs the page down to the specified place.
For example like on this page
like three botton elements on Violet background, in the top-right part of the page.

Please, halp me.

Are you using some javascript library? like jquery or something else…

Yes, but I am a junior wed desiner, and i don’t know how to do this.