This article explains the basics of using Microsoft Publisher 2021, 2019, 2016, 2013, and Publisher for Microsoft 365.
The Beginner's Guide to Microsoft Publisher
When you open Publisher, you’ll see a selection of design templates to help you jump-start your publication. There’s also a blank template available if you want to start from scratch.
Select the Built-in tab above the displayed templates.
Scroll down a bit and select Greeting Cards.