Pokemon Diamond WiFi connection trouble!?

Hi,I own a DS lite with Pokemon Diamond and am having some problems getting connected to WiFi. I currently own wireless internet access- which is Actiontec by DSL Gateway- but it's not compatible with Pokemon Diamond. I don't understand how to use a USB cable, so is there another way to connect at home using my current internet source? Also, if I were to use an internet hotspot, do I have to be directly in the store, or can I be in the parking lot or near the store (ex: Mcdonalds) ?Thanks so much! Michele