Poker is a card game in which players wager money for the chance to win based on a combination of their own two cards and the five community cards. While there are some strategic elements, the game is largely based on luck and there is not much skill involved (although confidence might get you through a job interview ahead of someone with a better CV).
In poker you need to weigh your chances and maximise profits. That means maximising value from your strong hands and bluffing opponents off their weak ones. The mathematical concept of risk versus reward helps with this, and you can learn about it by reading up on the odds and probabilities of different combinations in the game.
Whenever you are playing poker you need to pay attention to the reactions of other players. This can add a lot to the drama and plot of your scene, so focus on things like who flinched and who smiled. This will help to make the scenes feel more authentic and less gimmicky.
When it is your turn to act, you must say “call” if you want to make a bet equal to the last player’s bet. This means that you must place chips or cash into the pot. Alternatively, you can say “raise” if you want to increase the amount of money in the pot by more than the last person’s raise. Then other players must say “call” or raise their bets accordingly.