Flipping in a kayak (or "falling over") is part of the learning process, especially for beginners.  Like learning to walk, ride a bike, or snowboard - falling happens from time to time.  As our skills improve, frequency that we flip or fall, will be few and far between.  First, we should become comfortable doing a "wet exit" when it's upside down. This is covered at length in the "Intro to Kayak" class, and briefly in the "Kayak Roll" class; each in an indoor, heated pool.  The Wet Exit is incredibly simple and easy to do, and I'll demonstrate this procedure first, and will stand beside each person as they do it a few times.   It's very easy for the instructor to roll you back over, for the added assurance that you'll be OK.  It should get easier and easier, so that you're no longer afraid.  The "Kayak Roll" (or 'Eskimo Roll') is demonstrated a few tims in the "Intro to Kayak" class, but is beyond the scope of the 'Intro' class, thus is not formally taught.  To learn the Kayak Roll, check out the Kayak Roll class.  By practicing these skills, using good judgement and managing certain risk, we should be over-prepared for most adventures on flat water.