The Intro to Kayak clinic is the foundation for everything I teach. It's a required prerequisite for the 2-day Whitewater Weekend clinics and the 2-day Touring Kayak Weekend clinics. The Kayak Roll is a good next step after the Intro to Kayak clinic, although not a requirement for the Whitewater or Touring Kayak Weekend clinics.
While learning to roll is a good skill, it's not the best place to start. Rolling is a defensive measure. Good boat control, judgement and an accurate assessment of your skills will keep you from rolling most of the time.
You'll learn boat control in the Intro to Kayak and subsequent clinics. Those who complete the Intro to Kayak class have a much higher success rate in the Kayak Roll clinic. A few hours in the boat learning to do smooth and controlled wet exits from a skirted kayak will be money well spent. If you've spent little or no time in a decked kayak, your mind will simply be too distracted by flipping over and getting out to learn the Kayak Roll.