Beta-Progress is reset - so you only keep the Things from the Beta-Contract (Gunbuddies, 4 Playercards, etc.)
Skins you bought, and things you unlocked with Agent Contracts are gone for good.You should have received your Valorant Points back (with an additional 20% bonus) though. If you did not: Contact Support ( https://support-valorant.riotgames.com/ ) and keep a Proof of Payment at Hands - they will get you your points back =)
We're investigating a small subset of players who may have VP grants missing from the CB reset.