Hi Brandi!
Congrats on the weight you've lost so far! You'll find lots of support here to help you along the rest of the way! We have a 20-Something forum at 3FC under Support Groups and I think there might even be a college students thread somewhere on here, lol. People here are so nice, and they want the best for you, so don't be shy! Just jump right in! Newbies are always welcome! As for calorie counting, most people try to stay within a range of 1200-1500 calories a day. And exercise is a very individual thing. Some people love it and do lots of it; others do mild or moderate exercise like simple walking. You can't go wrong as long as you are moving! There is an app that many people here use called myfitnesspal and it will keep track of your calories for you, even including calories burned while exercising, so you might look into that. You can do this! Good luck!