Im very underweight, not anorexic, but very skinny, 186cm just 57kg, tried to go to the gym and consume 3500kcal a day and 1.25 times my mass, tips?

Hard-core fitness: You want muscle but probably not fat. You gain muscle by focusing on resistance exercises and perhaps using creatine. Many track-and-field stars are "underweight"; the "ideal weight" business subscience in any case and useless in describing athletes. Photoguy isn't complaining. Eat plenty of protein and avoid greasy, salty and fatty stuff.