Help Plzzzzz

Im small like I’m 5’0, never weighed more than 118lbs and in other words I’m small,skinny,petite, slim any name you can think of and I want to gain weight. Since forever I’ve never had a butt. All kinds of names have been thrown at me ( flat back, pancake, no ass at all) but it doesn’t really bother me anymore I jus say sorry I’m not born with a picture perfect body. So I wanna do this for me because it’ll make me happier with myself and yes I understand im fine jus the way I am and I shouldn’t let society dictate the way I see myself but it’s what I need for me. So beside squats and all that does anyone know any other ways to gain weight ? Like foods, drinks anything....🙂FYI i may be small but I eat like a grown man with three jobs but the weight goes nowhere