I ussually hear people say : I hope you are fine, I hope everthing will be OK....as wishs for someone, not to question someone. And people ussually reply : Thank you so much, I hope so...

I think you mean "Do you know a good reply / the best reply?" "Hope you are fine?" is not a clear question with an obvious range of replies. People often say "I hope you are fine". They are not usually serious about checking if you are fine or not. It does not need a reply. If someone genuinely asks "are you OK?", then you can say "yes, I'm fine", "I'm very well", "not bad" "not too bad", "hanging in there" "just great" or all sorts of other things depending on which country or generation you come from or how you are feeling. It doesn't sound natural to ask "are you fine?" Kind regards, Michael