This may not be how old-timers around here would do it, but I would put Giovanna Rosa Maria Teresa under "proper first name" (yes, it'll complain), and Giovanna Rosa under "preferred name". I'd also check the box for "no middle name".
The reason I'd do it this way is that the concept of middle names is murky at best, and almost nobody does it the way the U.S. (the basis for WikiTree's current setup) does it. According to the Social Security Administration, middle names are not technically part of your official name. In other countries, all of your given names are considered equally part of your name, and you're free to use whichever one(s) you want.