Posts on home page showing up as first post in all categories

Sorry this is not a theme issue but need help on this. My site is uniforms-shop.org/. This is a website for Uniforms supplier, the main post on the home page describes all the different uniforms it provides so naturally this post appears in all categories of uniforms but I want this post to appear as the top post on homepage but as the last post on categories post. How do I accomplish this? Any help would be kindly appreciated.

Any advice on how to improve the site will also be appreciated, this is my second site for a fashion niche business so not very informed.