Hi,firstly i would like to say have lot of fruits veggie and milk that will help build your immunity and this initially try getting into a 30 mins brisk walk which will help you build your stamina and once the stamina is built you can start on a more rigid regime of exercise.
Coming in shape steadily involves:
Stick to the rules and you will definitely loose weight.
#Cut back on sugars and starches.
#Eat protein, good fat and vegetables.
#Lift weights 3times per week rest days you can go for 30 mins brisk walk.
#Drink more water
#Choose small meals.
#Use small plates.
#Take good sleep.