How do I gain weight fast with supplements?

I am a 18 year old male who is 5’10” and weighs 122 lbs. I have a small chest and arms but decent abs. I want to increase my weight along with the mass of my arms and chest. Also I don’t have any equipment besides a doorway pull-up bar. I don’t know anything about supplements but I would like to use something such as creatine. I want to not look small anymore but I don’t want to risk losing abs. What would you recommend I use to gain weight and are there any exercises I could do at home that would help?