Using DBCA to generate database creation scripts

Invoke dbca . Select "Create Database" and then Advanced Options. Select your options to create the DB.

Select <Custom Database template> on Database Template page  (If you do not use custom db template, all other templates will result in a script that does rman restore from a backup that comes with the product). Selecting 'custom database template' will result in scripts built around "Create database" sql statement

On the creation options page, deselect Create Database and select Generate DB creation Scripts before you finish. Note the directory name where scripts will be generated.