Where do I find the round times and maps?

The Overview tab of each tournament: a schedule of every round with its start time, the map each round is fought on, and which round is next with a countdown to it. The Rules tab repeats the maps by round alongside the format.

Times are shown in your own timezone, so what you read is when it happens for you. Rounds are separated by a fixed interval set for the whole tournament, which is why a later round can start very soon after an earlier one finishes — plan to be available for the whole window, not just your first match.