You won't be able to print any documents (purchase orders, invoices, etc.) related to your project until your client has accepted your quote.
Once the quote has been accepted, both you and your client will be able to access the project's purchase order.
To download or print it, go to the "My Projects" tab of your Malt dashboard and then hover over the "view downloadable documents" link for each project in your list of in-progress projects.
A popup will appear identifying all of the documents available to download at that time. Simply click on "Purchase Order" to download the file.
Once the project has been marked complete, you would follow the same steps to download the project's invoice. The only difference here is that you'll want to navigate to the list of your completed projects to find this information.