Creating a New Category in Joomla
1. From your admin panel, go to Content -> Category Manager.

2. Next, select the New icon at the top.

3. Fill out the form fields with your category's info.
Title - the title of the new category
Alias - the alias of the new category
Published - toggles whether or not this will be visible to your site's visitors
Access Level - the level of access required by visitors to see the category
Image - you can choose an optional thumbnail to be displayed for the category
Image Position - choose whether the image will appear to the left or right of the category

You can also enter a description of the category in the box provided below this form.
4. Once finished, simply click the Save icon and your new category is created.