It's kinda sad that are ignorant people like you, but I understand boy. A lot of people are fit but their knowledge is limited, they think that what worked for them is universal. Even Justin Bieber has an 8-pack. I've had a friend who used to eat like a bear and hit the gym hard just to put some weight, which he eventually did... while on the other hand I was eating less than him and I was bulkier. There are different types of bodies with their pros and cons, not everything works for everyone (SURPRISE). Anyway, start with YouTube, Athlean X is a legit and great channel and it might help your ignorance if you are not too hurt to even give it a chance. You can also search for hard gainers and their routine.