A project or a folder can be configured to use a Style Document (revision). If a Style Document is configured the styles it contains are available in every document created within the folder or project. They cannot be changed from within such a document, they can only be applied. Refer to the ITP/MDK Repository Manual for a way to include style elements such as headers or logo's from a Style Document in your report.
At this point you need to make a decision. If you want to use the styles as used in the predefined projects you can just select most appropriate folder and create a new model document. If, on the other hand, you want to use your own styles you will have to create a new Style Document, select a folder, configure that folder to use the new Style Document and create a new model document in it.
Note
This new Style Document only takes effect on the already present models in the folder when they are re-created.