Create-A-Player
This mode is pretty self-explanatory. You will make a character and play solely as him through the season. Don't worry if your guy is terrible at first, this mode has a large RPG element to it so you can build out your guy over time.
Let the loses slide at first.
Your guy is going to suck in the early stages, it is unavoidable. It won't help if you get drafted to a bad team either. Just stick with it and in time you will be shooting baskets from half court.
Use up your drills when you can.
These give you points used to level up based on your performance. You can also use the points however you feel. If you can shoot like a pro, play the shooting drill and then use the points on other things like passing or dribbling.
Don't spam passes and shots.
Your performance is graded and you are awarded points after each game. If you make a bad pass you lose points. If you allow the opponents to complete a pass and then get a basket, you will lose a lot of points. It will take time to learn what you can and can not do. Scoring, completing passes, assisting in defense can all yield points, but you can lose them again very quickly so be cautious.
Set the game length longer.
Since you gain points as you play, the more you play the more points you will earn. This can also work against you if you tend to lose points as I mentioned above so make sure you are ready to play these longer games and that you know you can gain points from them.
Biggest tip here, be a team player.
You can't control the other people on your team but you can certainly help them. Pass, play solid defense, take the shot when you are sure you can make it. At some point your guy will be amazing and can hog the ball all you want. In the beginning this is not the case and you need to rely on your team.