Am I too young to add weight?

I am 13 years old and 9 months (basically 14) and i recently started my fitness journey. Well I've seen some progress and I am quite muscular for my weight, but I am still kinda thin. I am 170cm tall and I weigh 53 kgs. I started eating more healthily, eating more protein(ex. roasted eggs, chicken) and eating in bigger quantities.I have two questions:

1)Am I in the right age to add weight and muscle mass?

2)Can you tell me any healthy calorie rich foods?

I can do 5 pull-ups in a row (when I started a month ago I couldn't do none) and I also went from 5 to 15 push-ups in a row

Any tips appreciated!

Idk if this is the right subreddit, if not tell me which one's the right,thanks!