New Black Berry Help (Bell network)?

[Gotasecretm]

I just bought a blackberry off of someone. He said that he had it for a year then Bell sent him a new one cause his plan ran out. I am completely new with blackberrys and am just wondering if I will need to reactivate it or what do I do? Id rather have pay as you go but I dont know anyone other then Telus offers this. Also, can I switch providers to telus or no? Any help would be great! Thanks