Do not understand concepts of variables, classes, strings, and especially how to save data for later use when creating a program in java.

The attached file is the assignment I have been given to do. I can understand certain things, which I have attached in another file. But I don't understand some things and think i'm leaving something out, mybe some variables? somehow. As much help as you can give me with how to make the program work, especially the admit button, and hints for using java would be great.
Basically, what do I need to do to make it work?