cbc tries to connect to some existing bucket first to pull the cluster configuration, and by default uses default bucket, which does not seem to be exist in your case.
If you need CLI to administer your cluster, you have to use the tools, which come with the server distribution package (couchbase-cli). In your case you should use couchbase-cli bucket-create:
couchbase-cli bucket-create -c localhost:8091 -u xx -p xx \
--bucket=test1 --bucket-type=couchbase \
--bucket-ramsize=200 --wait