In order to assign a category to a post you need to go to your Admin Menu and click on ‘Posts’ and select the post you want to assign the category too.
Once you are on the editing screen, on the right hand side there will be a widget box called ‘Categories’. It will include all your current categories and the option to add more. To assign a category simply either choose the category it belongs to or create a new category.
TIP: You can pick more than one category.
Underneath the category widget box is a widget box called ‘Tags’. Here you can input keywords that your users will be able to see and search on your post.
Once you are happy with the categories and tags you’ve added, click the blue ‘Publish’ button.