How offline payments would works
First you need to active offline payments. So, login as admin and go to Theme Settings > Payments Settings and then select the offline WooCommerce.
Now, You need to active WooCommerce offline payment methods. Go to admin > WooCommerce > Settings > Payments and active the offline payment methods line Cash on delivery, Direct bank transfer etc.
After successful complete the checkout process, Order is received as a On Hold status. Now, after receiving the amount admin need to complete the order.
After completing order, the packages package will be updated. Same thing would be for job and services hiring. When admin will update order then job will be assigned to freelancer and both will get emails.