You can create, edit and delete paragraph and character styles.

Generally, authorized staff uses the EdAdmin4 to create, edit and delete styles.

Anyway, you can create and edit styles while editing text on the Articles and on the Pages main tab.

When editing styles have in mind that they are global on the system level, and possible used in many articles, also on not yet published pages. If you significantly change properties of any given style, articles that were brought to fit may turn into overset or underset.