From fabric document create-join-channel, when I execute the command
peer channel create -o orderer.example.com:7050 -c $CHANNEL_NAME -f ./channel-artifacts/
As @Phil said, you should comment out that line before you start the network. As documentation says :
If left uncommented, that script will exercise all of the CLI commands when the network is started, as we describe in the What’s happening behind the scenes? section. However, we want to go through the commands manually in order to expose the syntax and functionality of each call.
see the doc