You may go to Sales-> Orders and click on Add button on the top right corner to insert orders. You will have to fill in basic information of the customer, shipping information, payment information and add products according to SKU.
1. When the order is added successfully, it will not add new customers to your store. The system acquiesces the customer uses guest checkout. If you need to add new customers, please go to Sales-> Customers to add new customer and link the customer to his order.
2. Shipping cost and tax are not included in total value of the order. When order is generated, you may edit the order to complete information such as tax and shipping cost.