The Pawn Is No Kingmaker
If your pawn reaches the last row--called the eighth rank from white's position or the first rank from black's starting point--then it can promote itself. It can become any piece of the same color except the king.
Swap Meet
As you replace promoted pawns, it's possible to have more than one queen, or more than two bishops, rooks or knights fighting for your cause at the same time. Most decent chessboards come with an extra queen in each color just for this purpose.
Killer Queen
Because the queen's ability to move in any straight or diagonal line can't be matched, that piece is most often chosen to replace a promoted pawn. The queen can be a powerful attacking force from the eighth rank as play continues. Perhaps checkers is the reason someone might think a pawn could be kinged. In checkers any of your pieces that reach the opposing back row can be kinged.
Suicide Chess
Suicide chess is not for chess beginners, because it has some strange rules that traditional players frown upon. One rule is that the king is just a regular piece. It can be captured, you can promote a pawn to a king, and the powerful defensive move castling is not permitted.