Read everything, slightly confused

Yes, MFP calculates your calories minus a deficit. What did you set yor loss goal as? If you have a lot to lose, 2 pounds/week might not be unreasonable. If you've only got a little, your calories will be unreasonably low with a 2# expectation.

900 seems like quite a bit, I don't think my dinner is over 650: salisbury turkey burger, roasted baby potatoes, asparagus and a small brownie ...restaurant portions are typically pretty big. The only thing I like about chain restaurants is that they calculate and post calories for meals...pay attention & maybe only eat 1/2 if it is super high in cals?

Your weight loss goals, coupled with your activity level will determine your daily calorie recommendations. Always remember that it is not a requirement, but what is recommended to remain healthy. You are allowed to adjust it slightly if it is needed, but if you are adjusting anything, it should be based upon your goals and activity level. If you are sedentary (a couch potato with a desk job) then you are going to need fewer calories to fuel your activity. If you have light activity, like you go for walks, or have a job that includes physical activity, then you are going to need slightly more calories, and if you are really active, like a runner, bicyclist, race walker or like to do lots of exercise, then you will require even more in order to fuel you body's needs. To lose weight, you just reduce your calories to a level below what your body burns based on activity, but rarely too far below what your body needs to function. Determine your CURRENT activity level, then your weight loss goal, and adjust your calorie needs as necessary More activity will require more calories. Faster weight loss requires more of a calorie deficit. Don't shoot for losing too much in too short of a period or it will cause more harm than good.