Blank First Choice Select List

Hi

I am creating a community soccer registration form. One of the fields is a list of age groups (Under 4, Under 6, etc.) to choose for the child to be registered in. I want the first option to be empty or to have a value like “please select,” but not acceptable when submitting (this is a required field). I am having some trouble getting it to work.

I have tried leaving the value blank, but that can still be submitted. Any insight into this would be helpful.

Thanks!

-Blair