To be safe, I suggest you follow the steps in this link to ensure your state return was not electronically filed.
If you find your return was electronically filed, you should not send anything to the Franchise Tax Board.
If however, you find that your state return was not e-filed, you will need to print out your state return for filing. When given the option, select Official forms required for filing. California does require that you attach a copy of your federal return to your state return as well.
Please see this link for directions on printing and mailing your return in.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"