Your ~/.aws/config needs to specify the region, probably us-east-1, or some such.
Your ~/.aws/credentials file has to have your access key and secret key specified.
OR
Put your credentials in credentials.edn (and make sure it's ignored by git),
and your config in config.edn.
Once you've got your credentials sorted, take a look at the
software.justenough.aws-demo.orchestrator namespace to see a couple examples
of creating and interacting with AWS services.