Definition of pf
Pf means "preflop", i.e. any action that occurs before flop. Not all hands of poker necessarily see a flop, nor do all hands of poker always see a turn or river, but all hands of poker have action preflop. preflop is the action that occurs before the community cards are dealt (flop + turn + river). When playing preflop, only our two cards in hand count since there are no community cards dealt yet. When all the players still in the hand have put the same amount of preflop, we can then reveal the 3 common cards of the flop.
Preflop, the street best mastered
In general, the poker preflop theory is fairly well understood among poker players. It is the place where poker players make the fewest mistakes. The more you move forward in the hand, the more complicated it gets. Even at small limits, even the most novice players will still have a good idea of the optimal way to play their cards before flop. If we can give you a tip, try to be the player who raises before flop when you get into the pot action (in short, try to have the initiative, you'll have more success after flop).