How do you create and print cards in Photos? You used to be able to create it, edit it and then click "buy it."

As of Sept. 30, 2018, Apple discontinued it's print services. Instead there are several online firms that provide apps that work with Photos to create the same products. See this user tip:  Post 9/30/2018 Printing Options for Photos.

For books, if you're still able to create a PDF file for that book the following may be helpful: try holding down the Option key and click on the Buy Book button.  That will give you a PDF file that is the same as was uploaded to Apple when they were still offering print services.

 If you can there's a 3rd party book provider which used to do the printing for Apple as a sub-contractor, Mimeo, that will take PDF files created by iPhoto and Photos and print and bind books and calendars. 

Also you can upload the PDF file to PrestoPhotos which can also print and bind books and calendars from iPhoto or Photos pdf files.  They've been doing it for some time now.  

Use the PrestoPhotos or Mimeo links above for direct access to the PDF file uploading and book/calendar ordering page for each site.