Hey Oceana,
Congratulations on doing your first tourney. Quite a few teams never even make it that far...ironic isn't it?
There are plenty of drills you can do to improve communication. Don't think that you guys suck because you don't communicate...it's still a big problem for plenty of very good teams so that tells you it's an issue that will need constant attention.
One Drill you can do is to play a game against your second squad (if you have one) where your center back man (the main communicator) is not allowed to carry his gun. All he can do is talk to people (and hang the flag if need-be). That way he doesn't get caught up in playing the game and he concentrates on telling everyone what's going on and relaying what everyone else says, and directing people, telling them what he wants them to do.
For amusement, you make it mandatory that everyone repeats what they hear, and if someone doesn't know where EVERY member of the opposing team is, he has to ask for that info. If someone doesn't repeat a call, or you (as the ref/coach) walk up to someone and they can't tell you where everyone on the field is, you swat them gently with your squeegee and continue to do so until they do what you want. Do the swatting gently 'cause remember, they have a marker filled with paint in their hands...
Another drill you can do for one or two games is for everyone to breakout with their guns against your other squad, as though it was a real game, but everyone has their barrel bags on, and their guns off (masks still on). When they get to their positions, they call out what they see, and what they want, and they just go "bang, bang" with their guns and they move as though it was a real game...the ref pulls people he thinks are shot out, or should've been shot out. Everyone may feel silly, but it gets them focused on communicating.
Don't worry about codes. Use plain english (or Swedish or whatever) to communicate most of the time. Don't get too technical with your dead count, just keep track of the bodies. Until you guys get better you probably only need 3 codes, and you probably can get away with only one: your deadcount system. Like I said, don't get cute with your codes. If you forget your deadcount system just say "3 of them are dead, and 2 of us are dead!". When playing with another team, I usually stick with the "Bad Guys, Good Guys" system. That way everyone knows what I mean. If you don't play NPPL, you can tape your codes to the side of your hopper. Just cover the whole piece of paper in tape so the paper doesn't get wet with paint.
Good luck, I know you'll enjoy tournament play and don't forget "Shoot, move, communicate!" you should always be doing one of those three things, if not all of them at the same time
Ray "my head hurts" N.
