stretching

What is the reality of stretching and should you be doing it before you workout or after? Or should we stretch on non workout days entirely? I was having this debate with someone else and they said at their age they have to stretch or else they will get injured but another guy said it was bad...

I'm 22 years-old Very skinny lean 155 lb I started bulking up recently and eating 2000 calories more than I usually do. I'm eating a big meal from McDonald's right now but after I finish my stomach still feels empty. It's like the more food I eat the more I want to eat more. Can you explain why...

Do you recommend stretching in weight trainning? i need a routine for it