as someone who was skinny and is now in decent shape, i have to disagree with a great deal of this piss poor (or vague) advice.
ectos do real well with high intensity workouts, such as the physique clinic workouts for the skinny guys (think low volume, drop sets, rest-pause). 5x5 is a terrible idea because you aren’t advanced enough to truly utilize its greatness. you should be an intermediate before you try something like that. definitely focus on low-volume workouts.
and you do have to eat a lot - shoot for a number like 22*bodyweight to start, then see if you can gain 1-3lb/week. that’s how i got from 175 to 207 in a summer.