Flavor does not matter, presentation does not matter but the food shouldn’t make you sick, and should ideally have enough calories per day for the average person to survive (2000 kcal min).
Edit: I am not in any danger of starving or malnutrition, nor am I insolvent. I’m mainly asking this question out of curiosity on how people would approach a solution :)
For the rice, look specifically for “fortified” - it has things like vitamins added in. From there, unless you want to actually track your micro and macro nutrients, your best bet is to just shoot for a good variety, and that’s where things like food pantries will shine, cuz (for most of them at least) their inventory will be changing constantly, so it’ll force you to try things you wouldn’t normally have the desire or financial access to.
This is assuming your local area has food pantries - you’ll have some homework to do to find those kinds of resources. Also look into langar kitchens if there are any Sikh churches near you. I’ve never been to one, but heard nothing but good things.