If you were to become a total vegan, what is the smallest combination of food items needed to get all the essential vitamins, and fatty & amino acids?

You can't. If you become a non-supplementing vegan, you will ruin your health. Clinicians describe it as so common that there's even a "vegetarian's myelopathy", a disease of the spinal cord from B12 deficiency, with numbness and paralysis of the legs. If you want to be a vegan for moral reasons, you will need to supplement. Anyone telling you otherwise is a huckster. Protect your health.
It's about balance. Veganism is a lifestyle that includes no animal-based food and sometimes even clothing, soaps and cosmetics. Humans are omnivores by design, meaning we are designed to eat a combination of plants and meat. Not eating animal protein means that you have to be very careful and intentional about eating the right balance of plant material to stay healthy. There are lots of online resources to help.
Vegan. Quinoa, soy, lentils, tomato, orange, nuts, seeds, oatmeal, peach, plum ,prune, broccoli, banana, blueberry, acai, brown rice, .