Regarding your height or weight: Starting a Belly Dance class is like starting any other program of physical activity; check with your physician first! People who should definitely talk to the doctor are people with back and joint problems; obesity; pregnancy and, of course, people who haven't exercised for a LOOONG time.
Is there any "age limit" for starting a Belly Dance class?
Unlike a lot of dance classes, there isn't an age cap on starting a Belly Dance class. Some instructors will take children (but not me *) through senior citizens. The majority of Belly Dance enthusiasts are females between the ages of 20 - 55, but there is definitely some room for variation in this population.
The minimum age for our studio is currently 18, with possible exceptions in special cases (16 w/parental consent).
*) I love children. However, I've found that while children LOVE belly dancing, they have problems with learning a choreography, and since I teach choreography, children are not suited for my types of classes. We do not provide childcare, and don't allow observers. Thus no children, sorry.