How to get the most results from working out the quickest?

Follow a good beginner routine. Don't make up your own. Full body routines are generally best for beginners.

Eat enough calories and protein.

Since you dont want to lose weight, have a diet with moderate carbs, low to moderate fats and high proteins. Lift as heavy as you can. Do split workouts.

It depends, you would have to work that out for yourself. Follow a training plan if you can. Make sure you're using the proper form and technique for each exercise and not just being reckless.

Eat a high-protein foods before and after working out