Nutrition, Training, Regeneration....

To be able to get the best results in dieting and building muscles, you shouldn't break some elementary rules.
A big part of your success will be the right nutrition. Some people don't think it's that important, but they will be stuck after a while and won't make any further improvement if they don't change their diet. The balance between Protein, Carbs and Fats must fit your bodytype and you will learn to listen to your body, so you can intentionally give him what he needs.
The right training is also important. You should be careful not to do too much and exhaust your body, but you also shouldn't train like a grandma. Push yourself to the limits, but give your body the rest that he needs. Always use basic exercises at first and make a good split that fits your goals.
If once you found a system that fits, everything should be cool. But don't overdo it - your body needs regeneration! Don't force yourself to go to the train if you have pain or feel very tired - it will be contraproductive.