Where to find Payout / Invoices / Order details for an account?

All the payout data is available on the dashboard. You can find the invoice and the order.csv on the dashboard. 

You can view/download the same, please go to Profile & Settings and then click on Report. It will show all the payout details; against each record, you can see an action icon. Click on it to download the invoice and the order.csv file. 

Apart from this, if you want to see which order is paid, you can go to the event dashboard and then click on Report // Payout.