It's important to realise that Top Spin 3 is more of a tennis simulator than a tennis game. There are no tennis-themed minigames in the career mode and no unlockable naked tennis modes either. Top Spin 3 is all about the game, pure and simple.
With that in mind, it's also important to realise that it isn't really possible to just pick up the game and start playing. It does take time and perseverance before you'll be winning games consistently. If you're willing to put in the time and effort, and play through hours of tournaments, you'll be rewarded with a very in-depth and involving game.