House paint isn't like automotive - it doesn't need a "clear" to "protect" it.
Since all of Behr's paints are "enamel" which one did you use?
If you used Semi-gloss or Satin - you are fine with a primer and two coats. If you chose an eggshell or their "flat enamel" - you will need to recoat with something more durable - like the satin or S/G