Hey there!
My team has won the Spirit award in every competition we've gone to since 2011 so maybe I can help you out with this
Like some of the others said, Spirit is not merely being in the stands! But still that is a big part of it! For every minute of the competition have someone in the stands dancing! For the first practice day and whatever, it's not as important, but once serious matches start it's very important to always be dancing and cheering! Even in times where we haven't made it into the elimination rounds or have already been eliminated we continue to cheer
And in the hotel and at school the whole team is taught our unique dances. (Get some unique dances.)
But just as important, make a presence for your team! Our mascot is a ninja so in odd times we have the ninja running around, either giving free hugs or playing ninja with other teams. When the mechanics entered the pit our mentor would yell "Ninjas! Goggles!" And we all stopped and put on our goggles in sync. And we have a distinctive cheer, one person yells "Go Ninja go!!" And everyone shouts "TA TA KAI!"
So yeah! Make sure everyone in the whole arena knows your team and has seen you guys being happy and enthusiastic all over
Just be happy and fun and bring in the spirit! Good luck!