Hi,
First, you need to confirm where your content is being stored or synced.
You mentioned contacts, notes, and audio files.
- Audio Files: If the audio files are found in the Voice Memos app, then as long as you use iCloud backup, these will be synced automatically to your new device when you sign in with your Apple Account.
- Notes: If the notes are found in the Notes app folder iCloud Notes, these will also be synced automatically to your new device when you sign in with your Apple Account. However, if your notes are backed up with a third-party account, such as Google, then when you set up your new device you would simply sign into your Google account in Settings and enable Notes to have them synced again.
- Contacts: It sounds like you may have more than one account added to the Contacts app. You can confirm what accounts you have added in Settings or the Contacts app > tap on the back button in the upper left corner and you will then see Lists. This shows all of your contacts accounts and any lists you have created.
If you would like to store all your contacts in iCloud and have them sync automatically across all your Apple devices, you would need to make iCloud your default account for Contacts. When this is set up, all future contacts you add to the Contacts app will be backed up and synced with iCloud. If all of your current contacts are synced with another account, such as Google, and you want them to be synced with iCloud instead, then you can export those contacts to the Files app and then import them back to the Contacts app to iCloud.
If you've confirmed everything is synced with iCloud, then you can complete an iCloud backup on your old phone and then restore from that backup when you set up your new iPhone. If everything is synced with your third-party email account, then you would add it back to Settings when you set up your new iPhone using the steps referenced above.
