All booster packs have the possability of containing Valiant Dawn cards, even ones you previously have aquired but not yet opened. There’s also new Valiant Dawn Expansion Packs that only contain cards from the new set.
On July 30th-31st there will be Release Celebration tournaments; 9 total, of which 3 will be free to participate in. Events start roughly every 3 hours. The full schedule is here.
I’ve got some unopened packs, and currency to buy some new packs, so I’m going to dig in tonight and get myself some new cards!