The Retroid Pocket Classic is perfect for an 80s kid who grew up with Game Boys; he just didn't know it existed.
Select an option from Settings > Sounds & Haptics > Ringtone to set a new default ringtone. You can use a third-party app to create a custom ringtone. Select it as the default in the Ringtone settings ...
Instead of buying a new phone, try clearing some space, updating your software and changing a few battery settings.
Here's how to change your iPhone's default notification tone.