Couple questions about creating mailing labels

Description

I signed up for a UPS account through Paypal – and printing the shipping labels for the items that were paid for through Paypal went well.

Now I have an item that was paid through another method – how can I print a shipping label for it?

1. I tried setting up an invoice with a $0 balance, so it wouldn’t need to get paid – but it still wants a payment and I can’t get it to clear… won’t accept a payment of $0….. So I can’t get it to place where it’s « ready to ship ».
2. I can’t find my UPS account number to print through another portal – anyone know how to find it?

Thanks!