ERROR: printone is using a global data structure. It should receive the single object to print as a parameter, rather than receiving the subscript as a parameter. You must declare the array of object inside main. Class definitions are global, but not actual variables.
I understand that printone is supposed to take an object of type Juventus (i.e. void printone(Juventus j)) instead of relying on a global array of these and taking an int named count as a parameter. That means that line 7 of your second code snippet would look more like: printone(team[count]);
What Peter meant by passing something as an argument is to call a function with that something in a proper place between the parentheses. All your functions seem like they can already take an array of Juventuses...
If you just overloaded the assignment operator for your objects you could do a simple 3 line swap. If this is for school, why haven't you done that anyway? Show us you struct/class.