How Do I Update My Garmin Street Pilot To Have Updated Maps?

i just got a refurbished gps system 2 weeks ago and it doesnt have updated maps. when i type in babies r us, it leads me to their corporate office, same thing with other stores. it also doesnt have the current new roads that were made this year. also when i click on traffic, it asks me to plug in the traffic receiver. what is that?!?!?