"Confirming" means that the transaction has been recognized but is still waiting for the network to confirm the payment.
Once you see this status, you don't need to do anything else. You can close the account and wait until you receive your order by email. This will happen automatically once the network has confirmed the payment.
The duration of the confirmation depends on the transaction fee and the network load. Usually transactions are confirmed within an hour, but in rare cases it can take up to several hours or even days if the transaction fee is too low.