Having trouble with pagination

I use your theme here https://www.caracepatdiet.com/

I would like to create a menu contain posts in a single category. I put it in Tips Diet menu, using the category of the posts. (https://www.caracepatdiet.com/category/tips-diet/)
But no luck. Each post is in 1 different page nav, to read another post I have to click the next nav menu. How to put such as 8 posts in a single page using category (Appearance-menu-category)