All the content you create is automatically stored in warehouse, you can find Warehouse in the Hub. You can search for and filter by content. By clicking on a content section, you can see and edit the content. When you are done editing, click on save.
As soon as you edited your content, it will be directly adjusted everywhere where it is used. In Warehouse you can see an overview of all the places where content is used and when the content has most recently been edited.