Let users add (an exercise/image) multiple times

Good day!
I make a web-site for Teachers of English. Imagine Canva but instead of images/stickers, the users add exercises (drag and drop).

How can they add multiple instances of Ex.1 Group?

Maybe you would also be so kind as to explain how can I better organize the hiding of that input mess that you can see will come with each and every exercise… I have a Drag-And-Drop area on the right and theoretically I could change the state of Input_Group on Drop event but it will be a nightmare when I continue adding types of exercises… Thank you in advance