It depends how much of a beginner you are. A project I did early on in C++ was to make the computer be able to play a game of blackjack against you. http://en.wikipedia.org/wiki/Blackjack with the computer playing the role of the dealer. I found it a beneficial and enjoyable project and finishing it was an awesome feeling. But it depends how much of a beginner you are. You may not yet be up to making Blackjack?