My first order+some questions regarding payments processing, order fullfiment and shipment

Hello, so ive finally gotten my first sale! Hooray!

Just wanted to thank each and every one of you for helping me knowing or unknowingly in this journey of mine.

Just have some questions regarding payment,fulfillment and shipment:

1.Apparently the order is unpaid(What does this mean?) and etsy is still processing the payment and on etsy it says that i should wait before shipping the item since i actually havent got the money yet as far as i understand.However isnt this a hassle for the customer since it needs to wait longer for the item to arrive? Should i actually wait before importing the order to printful, who is my pod provider or should i already start the order?

2.On Etsy it says that i need to use their IOSS number with my courier. Is this the same as dispatcher?

Thank you and have a great day!