How many calories should I eat to maintain my weight?

Set up your goals on here to Maintain weight. Make sure you have all your info entered in correctly. Based on what you said, I would say your activity level is most likely Active. MFP will give you a set number of calories to eat based off what you tell it. You want to eat as closely to that number as possible. Monitor your weight over several weeks. After 4 weeks if you have gained weight, try dropping your NET calories by 100 for a few weeks and adjust if needed. If you have lost after 4 weeks, up your NET calories by 100 few a few weeks and adjust if needed. Remember you want to keep about a 5 pound window (+/- 2.5 lbs) so don't be worried if your weight is not exactly on point every single day. That is normal and will most likely be water weight, not actual weight gain.

By setting your activity level to Active, you are taking into consideration your dancing so I would not log that as exercise. I would recommend that you get a heart rate monitor for you HIIT cardio and log that. However many calories you burned, you should eat those back as well. If you are still worried, you can also look into getting a Fitbit or Jawbone Up or Body Media to further give you insight into what you are burning.

Maintaining weight is a lot of trial and error. Don't beat yourself up if it takes you some time to find what works for you.

thank you! I do have it set up here but it says around 2,200 calories. Should I never enter my dance as cardio? Because that is whay I've been doing and it has been giving me a net extremely low. Should I only enter my circuit training?

Since your dancing is something that you do almost every day, I would just include it in with your activity level. If you are including it then you would not log it because you would basically be counting it twice. If you would rather enter it in as exercise then reevaluate your activity level. Whatever you are taking into consideration when you set your activity level should not be logged as exercise. If you do not include it when you set your activity level then it's okay to log. And remember, you want your net calories to be as close to your goal a you can every day. Try to work more food into your diet.

Also, from what you are saying about your excerise, 2200 calories sounds about right. I'm a little taller/heavier than you and work a desk job. I try to walk a combined 60 minutes (I have a fitbit) a day and usually end up burning around 2000-2100 per day.

ETA: That 2000 or so calories I burn a day is total burn throughout the day, not just from what little walking I do. So sitting at a desk for 10 hours a day plus walking for about an hour ends up with me burning about 2000 calories. If you're dancing 4-5 days a weeks, you are going to be burning more than what I do.

First, I assume you are working with a doctor and nutritionist and I suggest you set goals with them. In fact, I'm tempted to say no more.

Second, if I were to say more I would say that in general, to maintain you enter your weight, age, current goals (0 weight change), sex, etc.

You have two choices. Set yourself as active and don't log exercise. OR set yourself as sedentary and do log exercise. I would do which you think will be least stressful and most likely to succeed for you. If you continue to lose weight, eat more or exercise less. If you start to gain, log your exercise.