Hi Israel,
Thanks for reaching out!
You are correct, tickets are essentially WooCommerce simple products, and no categories are automatically assigned to them when they are created. You can add categories however by going to the ticket section in the event edit screen, hovering over the ticket, and clicking “Edit in WooCommerce”. From there, you can edit the ticket as you would a typical WooCommerce product.
To create promo codes, you can use WooCommerce coupons, which you can apply to only a particular category of products.
Let me know how that goes and if you have any questions!
Thanks,
Jennifer