Rest
One of the most important parts of growing muscle is to let your muscles rest. That means sleeping adequately and eating properly while also letting your muscles rest for at least 48-72hrs before hitting the same muscle group again. When I was a teenager, I would hit the Bench Press every day for an insane amount of volume which would inevitably destroy my muscle gains and not see any progress. There is although evidence that supports training the same muscle group everyday and having progress but that would require having a very small amount of volume to cover each day (2-3 sets per muscle group). I would advise to stick to a Push/Pull/Legs routine which is sure to allow time for recuperation.
Technique over Ego
As you grow older and wiser, you realise that there isn’t really any importance behind being stronger than a random stranger in the gym. Why risk injury just to prove to your friends and others that you are stronger? Poor technique always translates into injury in the long run. So focus on your technique and slowly progressing on your lifts so you don’t learn it the hard way.
Intensity doesn’t always need to be high
Another way to injure yourself is to perform every single set every single day at the highest of intensities. Even though it is advised in order to create hypertrophy in your muscles, it is unrealistic. Not everyday is a good day mentally and physically, listen to your body and go accordingly. Studies have shown that even 30% of your maximum intensity can still produce hypertrophy gains. So next time you feel sluggish be the bigger person and give yourself a rest by performing a deload session. I know it’s hard in the society of “be better everyday” we live in, but deload days are as important as normal training days.
Don’t take advise from gym goers that don’t have a degree.
Having a nice looking body doesn’t always mean you know what you are doing. When I went to the gym as a teenager I would always ask “veterans” how to optimise everything I do. Even though some advice was legitimately good, the majority of them were bad and at some times dangerous. From “Don’t do deadlifts” to “Do biceps everyday” until I figured out what actually worked, god knows how much I damaged my body back then. If you ever need advice on how to properly train you should always search for evidence based approaches online and/or legitimate trainers with degrees that actually know what they are doing.
Don’t be afraid
When I was younger I would always avoid doing “dangerous” exercises such as Deadlifts, Back Squats and Bench Press. There is no danger in doing these exercises if performed properly. Hire a trainer to teach you how to perform these movements safely and start adding them to your routine. My strength gains skyrocketed after seriously training these movements in University.