YES!! Because you have both a main phase 1 and a main phase 2. If you do not summon a monster in main phase 1, enter your battle phase, complete your battle phase, then enter your main phase 2 and...
Usually, the tributes are announced in the parade and with Cesear Flickerman and the tributes can see the other tributes's weaknesses. And in the arena, the cannon goes off, signaling a tribute was...