I can get a great deal thru Samsung on an unlocked s10+. I've never dealt with a new unlocked phone. My plan is thru Verizon, do I just take the phone to them to activate after it is delivered?
Yes they will activate and put a sim in the phone. That is what me and my husband did we switched from Sprint to Verizon and already had unlocked from Samsung cause we knew we were wanting to switch carriers at some point.
If you're on Verizon now, just swap the SIM into the new phone, then call them and ask them to reprovision your account. (You'll need the IMEI number - just dial *#06# on the phone dial.) If the SIM is larger than a nanoSIM, you'll have to go to the store and get a new SIM (I don't suggest cutting them - even experienced techs, using SIM-cutters, sometimes mess them up.).