To transfer contacts from iPhone to iPhone, using iCloud is the easiest method. Ensure both iPhones are signed in with the same Apple ID/Apple Account. On both phones, open Settings > tap your name > ...

If your new phone no longer supports SIM cards, or you don't want to use them anymore, you can convert to eSIM instead. I started my career with CNET all the way back in 2005, when the (original) ...