Log into your OpenCart Dashboard
Go to Catalog > Categories
Select the "Insert" button in the upper right corner.
On the General Tab, fill in the fields for your new category (you can make changes at any time). The only field that is required is the "Category Name"
Click on the Data Tab and fill in the fields you want (these are optional).
Click on the Design Tab and select from the dropdown menu if you want (these are optional).
Click the "Save" button in the upper right corner.
At this point, you have created your first category! You can add as many categories as you would like. The following screenshot shows that the category was successfully created.