unfortunately, making games isn't that easy. For instance, adding new content just for this game means coding the required combination of ingredients. Then, you need to incorporate a new book text and animation, adding animations for the result and sounds for it. If you're not experienced with unity, I suggest starting with the basics, which are really easy and can help improve your programming skills and experiment with what you learn which is the most fun part. after that you can look at other peoples work and modify it, and learn from it, which is a great way to learn new stuff.
But if you realy want to help develop the game, you could create animations or write a text file for a book and pass it to the developer.
And I hope you passed your university exams