Hey @jyotisharmav
Ti start off with CA implementation, you'll first need to pass category as a mbox param inside user.categoryId parameter. Once you do that target starts tracking categories that user is visiting. Now, in audience you'll need to create audience as you showed in screenshot.
Lets say, you have passed category as shoes on shoes category/plp/pdp page and similarly on other categories. So when user visits shoes category it becomes his fav. Category. Later if he visits phone multiple times it'll become his fav category and shoes will be pushed as second fav.
To understand how algorithm works, go through below doc.
https://experienceleague.adobe.com/docs/target/using/audiences/visitor-profiles/category-affinity.html?lang=en
Now, it depends on you what do you want to show to the user who's fav. Category is shoes or pen..
Accordingly create experiences.
Hope this helps.