There are no tricks to be perfect in poker, because if there were, everyone would use them, and therefore no one would be perfect.
To get better, I suggest you to start practicing without playing for real money. And when you start to gain confidence in your own abilities, switch to low-stakes sites. Do not sit at the tables where the sharks play, because you will be eaten.
For beginners, I recommend the site I currently play on, Everygame Poker. It is the perfect poker room for low-stakes players. Read this Everygame Poker review if you want to find more about this site.
When you succeed in low-stakes games, go to the next level, go to the sharks' tables, and don't be disappointed if you lose, learn from them and become a shark yourself.
The main thing is to not put on the table more money than you can afford to lose. Do the math before you sit down at the table.