In order to gain muscle/increase weight you need to be in a surplus, but you don’t have to consciously track it. Try increasing one of your meals by a few extra “portions” (like a few more scoops of Mac and cheese) and eat more snacks. Remember that when you’re in a surplus, some degree of fat gain will always happen because it’s how the body stores energy
I think also just making sure you include protein when you eat is a good thing to do too. Not counting it, I don’t track because I know how bad it could get for me, but I do just make I have something that is known to be a source of protein when eating. A decently cheap one is protein, also a nice replacement for eggs.