I want to be more like captain america
Why do you want to be like Captain America?
I want to be stronger, I want to be more courageous.
It's perfectly fine to want to be more like a superhero as they are supposed to be idealized role models. As long as you realize you can't actually have super powers and instead focus on the morals of that character then there is no harm for you.
So you think that I can be more like Captain America?
That is an admirable person to look up to. Physically it is not possible, but you can still demonstrate the courage and kindness that they do to others.