How do I get my phone numbers from my old phone onto my new phone?

Peter P asked:


I think I have to take it into a Sprint store, but I’m not sure. And should I charge up the new phone right now, or will that turn it on, activate it, deactivate my old phone, and I’ll lose all my numbers? My old phone: Samsung A900, new phone: LG Lotus, and I’m with Sprint, if that info helps.