You don't. pokemon saphire was made before wifi existed.
you just can't
You can get it by trade from diamond/pearl/platinum or pal park it from ruby/sapphire/emerald or get it of a wifi event. See related link below to see when you can get him when you can go on mystery gift on your title screen (you will need wifi connection).
because you need better wifi
Probably not.
You find were you can use it
you get wifi connection and go into a cave and catch it
you have to have wifi connection to enter
hoenn region which is in pokemon sapphire,ruby, and emerald or you could it through wifi
you can go to the start menu and select wifi connections, and you have to have a wifi connection, like internet connection, or you can have a wifi usb for your computer if u have questions my email is crrogers17@gmail.com
There is no Starbuck's in Pokemon. What you are refering to is the fact that you get WiFi connection in Starbuck's Coffee. It is not in-game. Real-life Starbuck's has access to WiFi.
Put your ds near where your computer is wifi is interenet connection so find a spot near your computer that has connection.
You cannot.