Ive been trying to gain weight. if i gained weight eating some junk food would i gain less muscle than if i only ate healthy or will i look the same?

Yes: Muscle gain trumps fat gain Try a low fat, low salt, high protein diet., try using this "4 F s diet concept: fish, foul , fresh fruit and vegetables and fiber. plus 8-10 glasses of water/day.

Some basics: Muscle is made from protein which can only come from your diet. Fat can be made quite easily from consuming fat, carbs(sugar/starch) or protein. Muscle growth also requires exercise that puts strain on the muscle to trigger the increase. If you just want to weigh more, just eat more. If you want lean muscle eat a proper diet and work out.