Jiu Jitsu is offered in a lot of gyms across the United States because it is an effective self-defense technique that anyone can use when faced with a threat. If you want to learn that, all you have to do is find a gym.
One thing you should know when looking for a Jiu Jitsu gym is that each one is different. It is only in doing some research and asking the instructor some questions will you be able to find the right one for you.
You should ask the instructor to tell you a little bit about the school. They should tell you how long they have been in operation, how things are done here and if they are a member of the American Judo and Jujitsu Federation or AJJF.
Most students start out as white belts. In order to move up, a good question to ask will be what is their testing policy and what are the fees. In general, test fees should not exceed $60 and the cost should be the same regardless of the color.
It will also be nice to know the name of the head instructor and how many junior instructors there are present. Naturally, they will tell you the accomplishments of these individuals and you can check this out by doing some research on the web....