How can i put sidebar in single.php

Hello.

I made a single php file. for my main news.

So the file is single-main-news.php, and uses a category named main page.

When i click on it to show, i see the sidebar, and the sidebar title (news) title, but i cant see the sidebar links.

I tryed everithing but nothing works, could someone please give me a a hint or a pice of code how to start?

Thank you