Display posts on a page

That is simple.
Just go to Apperance – Menus.
There you should find the main menu that is displayed on your website.
From the left side select the category you want to display as button and press ADD TO MENU. After that drag and drop the newly created button from the button of the page to where you like it. Than press SAVE MENU.

That should do it. Now when you press on the new created button from the menu it will display all posts from selected category.

Hope it help.

Regards,
Valentin