I would like to identify the pattern of the purse in the image below, and want to know how to begin the chain number of the stitch. Is it a double crochet or single crochet? What type of yarn do I use for this?
This looks like tunisian crochet.
Here's an article about how to get started with it https://www.purlsoho.com/create/tunisian-crochet-basics/. Cotton seems to be the most common type of yarn for handbags. I'd recommend a cotton cord yarn for extra durability and to show off the stitch texture.