To all the nutritionally competent people here, do you know what specific foods or drinks would improve and beautify the skin?

Whole foods, especially plenty of fruits and vegetables. Limit or eliminate caffeine (can make your skin dry), alcohol, and smoking, all can make your skin look older and dryer than it should. Breathe deeply as often as you can (you’ll have to remind yourself frequently until it becomes habit), get plenty of exercise. Lots of water.