Yugioh duel accelerator?

so i just got finished downloaded the game and i cnt duel cuz the deck the game me only has 36 cards and i dont kno what to do or how to duel on there cz i cant join and i dont hav any bps to use it says i hav zero and idk what to do can someone help me? so i can play and get the last 4 cards to i can start to duel?