customer placed an order, didn’t receive an email confirmation

#1. When a customer placed an order, they didn’t receive an email confirmation immediately.
What settings do I need to configure to ensure that customers receive an email confirmation as soon as they place an order?

The email wasn’t in the spam folder or the regular inbox.
I tested it with my own email address yesterday, but the order confirmation didn’t arrive.
What settings do I need to adjust so that customers receive a confirmation email immediately after placing an order?

#2. In WooCommerce, the order status currently shows as “Processing.”
Does it automatically change to “Complete,” or do I have to manually change it?

Thank you for your prompt assistance.
Jessica