Most people focus on reps instead of lifting heavy weights, but reps only help you increase stamina and endurance. To build muscles lift heavyweights.
If you're not training with intensity, then your muscles won't get bigger or stronger. Quality of workout is not determined by how much time you spend in the gym but, by how intense the workout was!
I know a break between your sets is important but the problem occurs when you take too long breaks. According to specialists, the ideal rest is 2-4 minutes to maximize your gains
When Lifting heavy weights to build muscles there is no room for error, correct form is a must or you might face an injury. So it's better to take the lightweight & correct form and gradually increase weight.
Our Bodies need a small surplus of calories to repair and grow muscles. Eat extra protein, carbs, and healthy fats to help those muscles grow.
Rest is when your body builds muscles. After an intense workout, your body needs time to repair muscles, you need at least sleep for 7-8 hrs to gain muscles.