This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
When you say "I don't know where to start", I'm assuming that's not literally true. You have learned in your course how to write an applets, how to create graphics with them, and how to add buttons that trigger actions, right? So where exactly are you stuck? Tell us what you have so far, and we'll try to get you going again.