Hello, @naijapropertyhub,
1. Have you activated the option both on the payments page and on the Cash on Delivery management page?
Access WooCommerce > Settings > Payments and confirm the option is active. Then, click on the button “Manage” for Cash on delivery and check if the “Enable cash on delivery” option is ticked.
2. For the Shipping/Delivery Fee, Please read and follow the WooCommerce Documentation here: https://woocommerce.com/posts/set-up-shipping-strategy/ & this article as well: https://www.shipbob.com/blog/woocommerce-shipping/ it will help you in solving your issue.
Regards 8Themes Team.