Sizes:
12-18 months: Shoe size 5
18-24 months: Shoe size 6
2-2,5 years: Shoe size 7
2,5-3 years: Shoe size 8

Skill Level - Intermediate (you need to understand basic crochet stitches and pattern instructions)
Stitches used - chain, slip stitch, single crochet,half double crochet,double crochet and decrease.