It's not that hard to figure out. If you dont gain a pound or two in the next couple weeks, eat more. If you still dont, eat more. See the pattern?
But you have to track it. Its simple science that you need to consume more than you burn to grow. For you lean light guys, I could honestly care less about "clean" eating as much. If you get fat, you can adjust that, but you won't. I was one of those light guys. I know. You need the calories. Eat calorie dense red meat often. Get plenty of carbs. Keep the fat reasonable. Things like peanut butter can be your friend. I've seen guys that are light and lean fail time after time by trying to gain on chicken, broccoli and rice. Theres a time and place for that once you adapt your body to taking in the right amount of food