Proud to hear about your career selection. Congratulations on your selection. For better nutrition you can have milk and eggs (if you eat eggs) for better protein,
calcium consumption. Else you can have good quality whey protein 2/3 scoops daily depending on your physical condition and activity.
Next Steps
Have lot of wholesome carbohydrates like atta, bajra, joaw, millet, rotis. That will help you during your endurance training. Lots of fluids in the form of fresh fruit juices you can have too. If its available.