Eat

I don't usually get into nutrition because it's such a minefield. Everybody has an opinion. Many have qualifications. Many think qualifications aren't worth the paper they're printed on.
Anyway, here is my short list of nutrition advice for anyone who may be willing to listen.
1. If it had face you can eat it.
2. If it grew from the ground you can eat it. (if you can eat it raw and unprocessed).
3. Drink water.
4. Take multivitamins. Add: Zinc, Magnesium, C, Fish Oil, D3.
That is a pretty short list. The supplements are just to counteract the crappy quality of food, lack of sunlight exposure, and help combat any inflammation one may have.
It not exhaustive, but it's a good start. If you make it a basis and get some exercise, you should end up pretty healthy and fit.
That's all I'm going to say for now.