Start with Stitch Map Baby hat 1. The map provides you with the provisional cast on. This follow up stitch map shows how to use those stitches.
Attention: round 15 starts with a k2tog. The last stitch of that very same round has to be passed over the first stitch to keep the stitch count. Alternatively you could stop round 14 before the last stitch and follow this instruction for round 15: * sl1-k2tog-psso, yo, k2, K3, yo, repeat from *
Make sure to scroll down to "written instructions" and expand instructions section for details.