Before creating a package for the LMV321LILT, you should (optionally) create a category for it. This is done exactly the same way as you already created the component category.
Since we need to create a SOT23-5 package, let’s choose the following properties for its category:
Name: Small-Outline Transistor (SOT)
Parent: Transistor (let’s assume this category exists already)
With a click on Finish the package category is complete and after a moment the new category is ready to use.