To get to 90 will be a long grind a cost a lot of VC, there aren't many shortcuts.
Playing NBA or Pro-Am games give nice amounts of points to lvl up, the park is also a good option if you know how to handle the ball well.
Keep your eyes open for Double XP Days or even Double XP Weekends.
Time wise; if you grind a few hours a day, it's still gonna take a week or 2 at least.