Any tips to weight gain? 17F

I am very skinny for a 17 year old, my weight is 38 kgs and height is 5”3. I want to gain weight like reach till 45kgs. I cant go to gym cause i am too nervous to go to public gyms any advice?

I am very skinny for a 17 year old, my weight is 38 kgs and height is 5”3. I want to gain weight like reach till 45kgs. I cant go to gym cause i am too nervous to go to public gyms any advice?