The 'Warrior Cats' series is a sprawling universe, and diving in can feel overwhelming at first. If you're new to Erin Hunter's world, I'd strongly recommend starting with 'Into the Wild,' the first book in the original 'Warriors: The Prophecies Begin' arc. It introduces the ThunderClan and the forest territories, setting up the core dynamics of clan life, rivalries, and the prophecy-driven plotlines that define the series. From there, you can follow the chronological order of the arcs, like 'Fire and Ice' and 'Forest of Secrets,' which build on the characters and conflicts beautifully.
Personally, I got hooked because of how 'Into the Wild' balances action and world-building—it feels like slipping into a secret feline society. Some fans suggest jumping into later arcs like 'The New Prophecy' or 'Power of Three,' but I think you lose the emotional weight of characters like Firestar if you skip ahead. If you love deep lore, you might even backtrack to the prequel 'Dawn of the Clans' later, but it’s richer after you’re already invested. The key is to avoid the spin-offs like 'SkyClan’s Destiny' until you’ve got the main story down—they’re dessert, not the main course!