Hey @N67A
Yes, you have full control over the order and will be able to refund and cancel it. If your store isn’t live yet, or if you are concerned about being targeted by bad actors, I recommend enabling payment capture for the time being. Payment capture gives you a chance to review an order before payment is finalized, cancelling or refunding an order in this state means there is no processing fees you might need to pay.
If you are using Shopify Payments, you can find more information and the steps to enable this here: Shopify Help Center | Payment authorization and capture.