You should receive an automated email from Etsy immediately after purchase. There will be a link to the downloadable PDF in the email. Sometimes Etsy's automated email response is glitchy, so if you have any problem at all receiving your download, please reach out. If you no longer have access to the email associated with your Etsy account, I'd be happy to send the PDF to a different email.

When you purchase a pattern, you are purchasing it for the size listed in the item description. Some patterns have instructions for multiple sizes, some do not. You can find that information in the item description. Sometimes I can help you adjust for a different size than what is listed, but that is not guaranteed.

All that information is listed in the item description.

No! No pattern teaches you how to crochet, not even beginner patterns. I use the American Crochet Association's rubric to grade the skill level of my patterns. According to the ACA, Beginner patterns include "Projects for first-time crocheters using basic stitches. Minimal shaping". They make good first patterns to follow, but do not teach you how to crochet or how to read a pattern. Please visit https://www.americancrochetassociation.com/blog/59464/crochet-skill-levels for more information about skill levels.