Try to go here:
https://155.libero.it/pls/portal30/w155.confcell
there's not your phone, but you can try the configuration with some other Samsung phone, like the X830... Unfortunately you have quite a particular phone, which of course is not sold in Italy.
The fact you wrote "trough Sprint" means just you bought it with Sprint? Did you put the Wind simcard inside and does it work? You can make/receive calls with it? It could also be possible that GPRS is not active (it should be, but you never know if you cannot access the 155.it). If you you need to call 155 (free) and hope to find someone who can speak English...