This is my code

Please say me what do you think about my code. I prefer in my game use a method in my method printGuess is that good practise or not ?

Seems fine to me.

Do you think is a good think to work like that or I should use a variable to get the return of GetGuess() ?

Whatever seems clearer to you. Though if you make a variable and only use it to be passed into PrintGuess() the compiler will most likely optimise it away in the release build.