How to link to other parts of the site when using Github?

Question

GitHub

In general, I recently created a site using github, but the question arose about the implementation of links to other pages. I mean, I have a regular static page in my hands and I want to assign links to some buttons on it, but at the same time, so that the original site address is preserved. That is, simply create in addition to such a link "name.github.io" such a "name.github.io/name". How can I do this without creating a new repository?