The debate is set up to accommodate both teams of three, a judge, a timekeeper, and whatever audience there might be.
The CON team generally sits on the right while the PRO generally sits on the left side of the podium. The judge and timekeeper are situated a few feet in front of the podium while the audience sits far back to ensure that there is no audience interference in the debate. This layout ensures that distractions are a minimum in the debate.
The speakers for each team generally sit in the order that they speak, starting with the 1st speaker sitting closest to the podium, and so on.
All debates are set up this way, so it would be a good idea to just recognize what the set up looks like.