I'm 22 and will start working out for first time ever, I'm aware you the human body develops muscle even but i need an advice on the best routine to get a meaty chest that will look good under my shirt.
I see a lot of new lifters following a 5 day split workout routine. That will work but in my opinion, you can make muscle and strength gains much faster by doing full body workouts 3 days per week. Being new to lifting, you don't need a huge amount of volume to stimulate a muscle to grow. By doing full body workouts 3 days per week, you are stimulating a muscle to grow 3 times per week verse just once per week in a split routine.
I would do a simple workout like this Monday Wednesday and Friday
squats 5 x 5
deadlift 5 x 5
bench press 5 x 5
over head barbell press 5 x 5
wide grip chin up 5 x 5
That workout program will not only give you a meaty chest, but also full round shoulders, a wide back, big arms and big legs.