I get a load of staples in like dried herbs and spices, stock cubes, chopped tomatoes, lentils, different types of tinned beans, veg, as well as rice, pasta and noodles. That makes the base for most of my main meals. I will use the tinned chopped tomatoes as a base for chilli, pasta sauce, curry and stew, and then just add stock, herbs or spices, and various veg and legumes.
You can get yeast flakes to add to food to get your vitamin B12, a lot of vegan food is also fortified. For iron you can get that from foods like tofu, pumpkin seeds, quinoa, cooked spinach, dried apricots and white beans. Eat then with vitamin C rich food as it helps the body absorb iron.
As for social life the only time it really matters is when I'm going out for meals. Most restaurants are happy to accommodate, but if it’s a planned meal I will check the menu online, and phone ahead to make it easier when I arrive.