Assigning posts to specific pages

Hi there

I would like to find out how to add posts to specific pages.

Let’s say I wrote a post about fashion and want to add it to the fashion page in the blog dropdown.

How do I do that? Which plugin can I download that I don’t have to upload to the plugin directory because I don’t know how – I need a plugin that I can activate within the plugin page. I don’t want to create a menu and assign categories to it because it changes my top nav bar completely, I need for the pages to remain in the dropdown and not to be displayed across the nav bar

Please assist in a simple manner – I am not a web designer and I cannot read code. However, I did build my site from scratch.

Please view the blog dropdown menu.

My blog URL is candyflossgirl.co.za