Open Warzone, then Battles. The tabs are Live, Upcoming, My battles and Finished. You can filter by chain and by battle type. The first live battle is shown large at the top.
Press Open fight on a card to open the battle page. It shows both coins, the countdown, the score, and the Vote and Boost buttons. Scores update live. Below are tabs for live comments, all comments, supporters ranked by Boosts, the rules and the prize pool.