The first thing to do is make sure you don’t lose your mind. And by that we mean your data. Back everything up before you wipe it from your phone.
On the PC, be sure you have the latest version of iTunes installed. Then connect your phone to your computer. When it shows up in iTunes, choose whether to back up to iCloud or your computer. (If you want your Health and Activity data to be included in the backup, check off Encrypt iPhone Backup and create a password when prompted.) Then select Back Up Now.
To back up directly from your iOS device, go to Settings, select your name, then tap iCloud. Scroll down to iCloud Backup > Back Up Now. If you toggle iCloud Backup to on, it will automatically update photos, accounts, docs, Health and HomeKit data, and settings when your device is plugged in, locked, and connected to Wi-Fi.
Then, when you get your new iPhone and power it up, you can choose to back up from iTunes or back up from iCloud, which will populate your new phone with all the apps and settings found on your old device.