My friend in gym told me not to begin abs training too soon, as I have lean body. He said if I start making abs now, I will face difficulties later making abs larger. Is it true?
I don't see any reason why you shouldn't do ab workouts. But anyway, you shouldn't focus on one muscle group, doing a broad range of workouts is better.
I've never heard of this being true. It also doesn't make any sense to me. I'm no expert but I've heard & read a few things. There are so many myths floating around in the fitness world that you could probably never hear them all, so definitely do some Google searches and get the full story when you hear something like this.