i am wondering how do i get body fat? what kind of food do i need to eat to get it?

eat alot of carbs?

Yes a lot of bread and meat, and well you need to maintain a good diet as well so dnt forget the veggies

i am wondering if McDonald's food okay or not.

i am wondering if McDonald's food okay or not.

McDonalds "Food" is not even Food, nevermind having any meat....
(they have been raked over the coal on that several times on that and still do it)

i am wondering if McDonald's food okay or not.

I wouldn't recommend eating McDonald's food on a consistent basis. It isn't healthy nor is it likely to be economical. I think doing some online research would be a good start to finding what kind of diet will best suit your goal.