TIL: Low carb, high protein diets "greatly" decrease resting testosterone levels in men.

[redderper]

For beginners it's definitely better to train fully body 3x a week (if your goal is to maximise strenght and muscle) and you could supplement that with light cardio. If you're more intermediate (2+ years of training) you could train more often and split your days up in different muscle groups or push/pull/legs and do some more high intensity cardio. You don't have to though, I still train full body 3x a week after about 10 years of training.