Need help with creating add button that would create a card pop up

I want to implement a note taking cards in ReactJS but not able to come up anything on how to start. Does anyone here know how I can do that?

It is almost always a good idea to share what you have so far with us so we have a little more context to help answer your question. And to make it easy, you should either put your code in something like codepen or create a repo in github and then give us the link.