Your go to for caps. OR old navy their sister store
My toddler is 20 months with a big head and fits the size small/ 2-3 size caps. They’re SO cute and always under like 15 bucks.
Toddler Hats - Gap
Everything in this brand. I know it’s pricey but I’ll let you know when I find a dupe. For now, you won’t regret it. It’s magic.