The ONLY way your new phone will find and pair with your Bluetooth devices (it doesn't make any difference if they were paired to your previous phone) is to put them pairing mode per the manufacturers directions to pair them.
Lawrence Finch provided a link which explains how to pair Bluetooth devices. Keep a copy of that. Every time you ever get a new iPhone, you will have to put your Bluetooth devices in pairing mode, then open Settings > Bluetooth > look for the Bluetooth device and tap it to pair. You will never get any device paired until you put it in pairing mode.
If you don't have the pamphlet which came with the Bluetooth Devices do an internet search on how to pair the device by the device name. The user guide for every Bluetooth device I own can be found online and the user guide will give you the directions on how to put in pairing mode.