Setting up new MacBook 12"

When first setting up my new MacBook 12, Migration Assistant turned the following message when I chose to migrate my files from Time Machine (external Samsung T3): "Your System needs to be updated" And then: "The selected backup was created with macOS 10.14.5. It is recommended that you update this machine before performing the migration." I'm not sure what this means and fear I might loose my backup if something goes wrong. Anyone encountered this and any advice?