From the Tournaments list, tap "+ New Tournament" and pick a type: Regular, League, or Multi-day. League isn't built in this app yet and shows a clear "not yet available" notice instead of a dead end.

A Regular tournament asks for everything up front: name, game type, date/venue, currency, entry/rebuy cost, max players, late-reg window, seats per table, starting stack, and blind structure. A Multi-day tournament asks only for the tournament-wide basics (name, game type, currency, entry/rebuy cost, max players, staff) — date, venue, seating, and blind structure are all set per flight on the very next screen, since a multi-day event doesn't have just one of any of those.

See Tasks → Creating a tournament for the full step-by-step, and Reference → Tournament settings for what every field actually does.