There are a couple of ways to add new cards in Wagn. (Note: On most Wagns, you'll need to have an account and be signed in to create cards.)

At the top of every page is a Search bar. Click in it and type the name of the card you want to create. Wait a moment, and a menu will drop down.

Click on the last item and you'll be offered to create the card:

You can write something in the big box if you like (and if you're curious about the type menu, see card type). When you click the "Create" button underneath the text box, you'll get to see how your new card looks.

The second way to add a card is to make a link to a card that doesn't exist yet, by editing some other card. The link will be red (links to cards that do exist are green). Clicking on a red link — for example, one that says fun with Wagn — will get you the same offer to create a card as above.