There are many complicated formulas that you can use to figure how many calories to eat in a day. A more common, easy way is to eat 10-12 x your goal weight in pounds. For example, if you want to weigh 125, eat 10-12 x 125 or 1250-1750 a day.
I lost 35 pounds by eating 1200 calories a day with no exercise. The first 25 pounds came off in 5 months. The last 10 took about another 5 months. The closer you get to goal, the slower weigh loss progresses.
To keep the weigh off I eat between 1350-1400 calories a day. I’m 5’5” and 125 pounds. I use a free program on the net at [url]www.******.com[/url] to keep track of everything. It helps a lot.
Since you want to lose relatively quickly, I’d suggest 1200-1400 calories.
As far as the exercise goes, I don’t know how much you should use the elliptical. I’d suggest at least 3 times a week for 20 minutes or more.
Good luck to you