In your first season aim to win all the minors and possibly a major or two, concentrate on training and max out power,forehand, backhand, speed and precision. In your second season continue to train and distribute the stars as desired (serve, stamina and reflexes id recommend personally) but aim to win all the majors and any "special" matches such as the tennis academy naming one etc, this will give you silver and gold stars.
When you max out 60 bronze stars you will get an invitation from a billionaire to a private match, its vs your rival and winning it is almost essential to maxing out all your stars in gold. By the end of your second season or beginning of your third you should have all gold stars and be well prepared to compete in slams and masters. Keep entering and winning minors and majors as well as the slams and masters.
If youre losing a match or training session quit to dashboard BEFORE the game can autosave.
At the end of every season youll be presented with your career points up to that point, hopefully by the end of the 4th or 5th 1000 will have been earned and you can sim to the end of the fifth season.
As DenXD pointed out, playing as female also makes it much easier both as you dont have to play as many sets and or have to face Federer.