Valorant's Episode 7 release on June 27th will come with a bunch of changes to how you earn and unlock in-game rewards. Riot says they're pretty simple stuff that you'll figure out as you go, but if you like me want to understand things before you try them here's the short story on what's changing.
Daily Missions have been reworked, and Agent Contracts are going out the window. So finish any outstanding Agent Contracts before June 27th. There'll also be a new in-game currency called Kingdom Credits to earn and spend from playing games—but it has a cap, so you can't hoard it.
The biggest changes are those tweaks to Agents and their cosmetics. Agents can now be unlocked during a 28-day Agent Recruitment pass that (automatically) happens after each one releases. They'll still take about the same amount of time to unlock, and you can still spend VP to unlock agents immediately.
Kingdom Credits are going to be the new in-game currency, and are earned for playing in any mode, with a bonus if you win a round in round-based modes. They're totally free, and accrue alongside the separate XP for Battlepasses and Agent Recruitment. They can be spent to unlock Agents, Agents' cosmetics, and accessories from previous Battlepasses: Gun Buddies, Player Cards, Sprays, and Titles. (No gun or knife skins, though.) The things you can buy in the store will be randomized, unique for every player, and rotate on a weekly basis.
The old rules for Agent Contracts now actually apply to Agent Gear Tiers, which is where you can find cosmetics if you're not unlocking them with Kingdom Credits.
Finally, the whole system of Daily Missions has been reworked. They've been broken into Checkpoints, and you earn progress towards them by playing any game mode. You just play whatever you want and progress toward them automatically. Daily Missions also stack up, and you get catch-up bonuses, so you're not penalized for not playing every day. (Thank god for companies who end that vile practice.) Daily rewards will be both XP and the new free currency, Kingdom Credits.
If you've got more questions then jump on over to Riot's Valorant website for a Progression Update FAQ.