Do I need to cancel original service in order to add new subscription package?

I originally only had the remote admin subscription however I added on the hub protect for the yearly price. I now see I have both subscriptions, one for the annual and one for the monthly to be billed in the future. Do I simply just cancel the remote admin monthly subscription?

Yes, switching between services doesn't automatically cancel prior service. The original
subscription must be canceled from my.hubitat.com.

Check out this document for more details: How to Cancel Subscription Services | Hubitat Documentation