Do you mean from one WDW resort to another? If so, that's quite easy. Have Bell Services send your baggage from your first resort to the next. The transfer will take several hours. If you send it in the morning, it will be at the new resort by that evening. If you have them transfer your luggage for you, then you can use Disney transportation to get yourself to the new resort (with Disney Springs or a park as the intermediary). Alternatively, if you want to keep your luggage with you during the transfer, you can take a taxi. They're everywhere at WDW.
Magic bands are like credit cards stuck on your wrist. Your magic band just tells Disney who you are. When you scan a magic band anywhere in Disney, Disney looks up your info and then let you do things such as open your hotel room door, get inside Magic Kingdom, use your dining plan credits, or buy something. If you have 2 reservations you will be offered 2 sets of magic bands. They are completely interchangeable. Go in your "My Disney Experience" app on the computer and you can pick the color of your magic bands. You should do that immediately so that you have the bands before your vacation arrives. That way you can get on the free bus at the airport, and you can skip front desk and go directly to your room if you give Disney your cell number. Disney will text you your room number and a map to show where it is. You don't need to activate them anywhere; they will be activated automatically.
