Before the game begins, you must decide who starts as the button. The button is a rotating position in poker, often denoted by a small plastic chip that moves one player to the left after every hand. In a home game, you may decide this amongst yourselves, but in a casino environment, the dealer will deal each player a card face up, and the player with the highest card is the button. In the event of a tie, the suits are counted, with spades being the best, then hearts, then diamonds, then clubs.
Once the button has been decided, the two players to the left of the button must post the small and big blind; the small blind being the player directly to the left of the button and the big blind being the player two to the left. These are forced bets that happen at the start of every hand before the cards are dealt as a way to create action. The size of the blinds will depend on the stakes you are playing and the format of the game. In some games, all players are also required to post an ante, a number of chips equal to a small portion of the big blind. This is common in poker tournaments.
After the blinds and antes have been posted, the cards are dealt. Each player is dealt one card at a time face down, starting the player in the small blind (the direct left of the button). The cards are dealt clockwise around the table until each player has two cards. Once every player has two cards, the betting round can begin.