I also learned on Kite Beach in Cabarete. It is very crowded. The kiting area is about the size of 3 football fields lined up end to end, and there are typically around 100 kiters there each day. Maybe about 50-60 on the water at one time. Generally, this area isn't like that one island in the pacific where locals try to run everyone else out of the water. The locals in Cabarete are very friendly. Most of them work at the kite schools, or hang out at the schools during low wind with their buddies. If they were constantly intimidating the tourists, the many schools and instructors would be on their case pretty quick. Kiteboarding is the main draw for the region and tourism provides the bulk of the local economy.
The beauty of Kite Beach for a beginner is that the wind is typically constant, at a good velocity, and not gusty. It's hard for a beginner to learn in >30knot winds, and also hard to learn below 12 knots. Ideally, the wind would be steady at 20knots. I was there for a week, and for 6 of the days we had ~20knot steady winds from about 1pm-4pm. Before noon, it was typically 10-15knots, and after 5pm it was getting up to 25-30knots.
There are always people ready to help you out on that beach. Sometimes it is because they are just nice. Other times it is because you might be endangering others. There are literally 10-20 instructors on the beach at any given time, so there are plenty of skilled people to lend you a hand.
The food on the beach is NOT CHEAP. The locals cannot afford to eat at the restaurants that tourists frequent. Further into the city there are more economical options selling more typical Dominican fare (rice, black beans, chicken, plantains). Throughout the Caribbean, the Spanish speaking countries refer to what the locals eat as "tipico", "platos tipicos", or "comida tipica". Ask locals (those not working at a beach restaurant or hotel) for places that serve this type of food and it will be cheaper, but you might be venturing through areas that aren't as safe for tourists, especially after dark. If you just want good food at typical everyday America prices, some have already been suggested here for $7-15 per meal. The nicer beach restaurants will be $15-35. Don't expect to get a decent meal for less than $5 like some other places in the Caribbean.
Now for the negatives. The water is deep. Deep water means larger swells. Fortunately, kite beach has a protective reef that helps prevent really large swells with breaking waves, but the swells still get to about 2-3 feet, especially at high tide. So when you are learning to body drag off shore, the beginner will need to learn how to body drag with his head turned and not looking up at the kite, unless he likes to drink salt water. The next negative is that during the summer, the waves start to erode the beach away, and it gets very small for the number of people. For a beginner, this means that launching and landing on the beach are a bit more tricky due to being forced right up next to the trees that cause turbulence. Not a problem in the winter when the beach builds back up. The last negative for a true beginner is that the beach and dominant wind direction is oriented for goofy foot water starts. This is unnatural for most beginners who typically prefer a regular stance.
After learning there, coming back home and riding the flat freshwater was a dream.