What should I choose?

Im in the hospital for an eating disorder, well used to have an eating disorder, but some people get to go a restaurant for lunch and make food choices that meet their exchanges (milk,protein,fruit, etc.) and i have three starches, I planned on getting a lunch meat sandwich, wich most likely will count as just 2, then for my third i wasnt sure if i should get an 8 oz ginger ale or sprite or a side of soup, i would like to limit the amount of food i eat because i also have three fruits and may end up eating fresh fruit along with 8 oz of juice and 8 oz of skim milk, which should i chose? the ginger ale or sprite or the side of soup?