Hi cookbookaddict2020 (great name!) - you use Bookmarks for that. We have a fixed Bookmark, "I want to cook this", which you can tag anything you see of interest. This will change the chef's hat icon before the recipe title on your Bookshelf to orange. The other fixed Bookmarks are "I've cooked this" which changes the chef's hat to green, and Favorite recipes.
In addition you can create any personal Bookmark that works for you. Birthday cakes, Thanksgiving sides, daughter's favorites, etc - whatever makes the most sense to you. You can then add those Bookmarks to any recipes you see in your searches. Then when you want to see the recipes in those Bookmarks, you select it from the My Bookmarks filter under Only Show in the right sidebar on your Bookshelf Recipes.
If you would like to learn more about Bookmarks, please take a look at Tutorial 4, which you get to from the green Need Help? button at bottom right (not available on phones). There are also several pages on Bookmarks in our Help.