Which tournament?
Let's take CC freeroll for example: 75BB starting stack and after just 3 lvls (in case you didnt lose a single chip) you are down to 15BB. If you play aggressive, see all flops etc, you are likely to lose, so being tight pre flop is probably the correct strategy.
Let's take some deepstack, rebuy tournament: you have tons of chips early, stack that is around 200BB, with the opportunity to rebuy for the first few hours. That means there is room for a lot of 3-bets, or 4,5-bets pre flop. There is a lot of room to call to see the flop, with marginal hands like 65s for example, that you can't really see a flop with in freeroll.
With all that being said, try to be dynamic, and change your style accordingly, in this case, according to the type of the tournament (regular or knockout), stack sizes, speed etc.