How to add “bookmark” links to pages?

I want to be able to have a “contents section” at the top of the page, with each section listed i.e.

Section 1 (link to section 1)
Section 2 (link to section 2)
Section 3 (link to section 3)
Section 4 (link to section 4)
etc

Section 1

Blah Blah Blah etc.

Section 2

Blah Blah Blah etc.

etc etc etc..

Here’s the page:

https://www.lamson.com.au/new/?page_id=28