Do I need to transfer my SIM card if my current iPhone transfers info to my new iPhone ?

If your SIM card is still installed in your old iPhone then the cellular service is still active on the old iPhone. Your old iPhone transfers/syncs information to your new iPhone because both iPhones are connected to the Internet and are signed on to the same Apple ID. With this setup, you will not be able to make or receive phone calls with your new iPhone. You will also not be able to connect to the internet over a cellular network with your new iPhone because there is not an active SIM installed in it.

The answer to your question is a YES. Please transfer the cellular service from your old iPhone to your new iPhone by transferring the SIM card.

Axel F.