"how to prepare"

hey chess.com -i wanted to ask a qiuck  question.In 3 weeks i have a big chess touriment.i have studyed with books and played alittle.But everybody says i need to prepare hard and fast before i get behind a board.

      i never get what that means? how do i prepare for a touriment?

when i think of preparing for a touriment i think :

1.play a whole lot

                  or

2.study  a whole lot

   well since i dont know,i am asking all of you guys     "how do i  prepare for this touriment"      "what is preparing for chess"  and   "what do i need to study good" i  thank you all for the help

                                          dylan2009-thanks