If you are planning to have just one performance on a single day, the performance date will be displayed at the top of your Home page as shown below.
If you would prefer not to have this date shown, this can be hidden by navigating to the Colors tab on the side menu of the Website Editor. Move the opacity button all the way to the left as shown in the second image.
Once you've done this, the result should look similar to the final image below.
You can then overlay text using the text editor as explained in this article below: