Hi there Jwill72,
Apple One is a great plan to bundle together a variety of Apple services into one monthly subscription. When you set up Apple One as part of a family share group, the organizer of the group holds the Apple One subscription and shares all services with everyone else. If you already have subscriptions, such as to Apple Music, it will automatically convert over to the family Apple One subscription. You should not have to do anything special, and you should not lose any of your existing content.
More information can be found in the following Apple Support resources:
Bundle Apple subscriptions with Apple One - Apple Support
Set up Family Sharing - Apple Support
Share Apple and App Store subscriptions with family members on iPhone - Apple Support
Have a great weekend!