A Season for Rewards
When you first start playing, you'll see a number of tempting options, but you should focus almost exclusively on clearing seasons. The reason is that your team doesn't yet possess enough skill to shine elsewhere, but you can earn coins and other rewards as you clear seasons, and that will quickly allow you to turn your attention to other endeavors.
Defense Is Key
Offense can be fairly easy, whether you're playing yourself or having the AI act on your behalf, but defense gets tricky. Early on, spend most of your time figuring out how to steal most effectively (guarding is good for more than just blocking shots) and don't make it easy for your opponents to score. If you can get good at defense, you've just mastered the trickier half of the game.
Team Play
Particularly early in the campaign, you should be working to build up a solid team. Don't sell anyone, and just focus on adding as many players to your roster as possible. Watch especially for players with a rating over 60, which you may be able to purchase on the cheap as a great way to get going. Then, once you have a solid team, you can worry about completing sets and finding superstars.
Various Gameplay Tips
We all like to play offense but in this game defense is the key. Early on, spend most of your time figuring out how to either steal or play hard making your opponents difficult to score.
At first focus on clearing seasons because your team doesn't yet possess enough skill to shine elsewhere and you can earn coins and other rewards as you clear seasons.
Also build up a solid team instead of hunting for star player. Focus on adding as many players to your roster, the ones with rating score above 60 cost between 200-500 coins, as possible.
By completing achievements you'll receive coins as an incentive, card packs and other such rewards. So, make sure you know achievements you need to finish.
Use Auctions to make money by selling high and buying low.
Learn special moves like spin moves, fadeaways, behind the back and so on for clear dominance over opponents players.
When the game is on in the upper right corner of the screen you can find play button that allows you to use auto play option so you don't have to play each and every game manually. Especially useful for games when you know you are a better team.
Complete the sets for more coins. If you can try completing a team and you'll get coins as reward.