Can you overlay an ad on home page or have a splash page?

Hello –

I’m not sure if you can do this or if it is the proper terminology BUT thought I’d ask. I have a bradford magazine theme which is working great. We use the wordpress theme as if it was just a regular site, not CMS. There is a registration for classes at our facility on August 5th. What I would like to do is have the photo and AD be displayed first thing when people come to our site URL. I thought initially I’d try redirect plugin but that doesn’t work.. then it was suggested that I create a static page but when I do this the ‘home’ page (which is a POST) disappears.

Is there a way that I can do this?
Like have a Lightbox open when someone goes to our site and display the Ad automatically?

OR rather than the home page appear first thing the page with the ad appears? (that leads me to the redirect plugin I thought was the answer). Like a splash page?

Any thoughts?

Regards
George