Create and Assign Categories for a Blog Post

Click "Blog Posts"

Hover over any of your blog posts and click "Edit"

Ensure you are on the "Post" tab

In the Categories area click "Add New Category"

Type the name of the new category in the "New Category Name" field.

If desired, select the parent category you would like the new category to be under

Click "Add New Category"

Select the categories you would like your blog post to be assigned to

Click "Update" to save your changes