[harness-ci-cd-zero-to-hero guide]: 1) 'Connector not found' means the connectorRef in YAML does not exactly match the connector name you created. 2) 'No eligible delegates' means your infrastructure does not match any delegate: switch to Cloud infrastructure instead of Kubernetes/Local/VMs. 3) projectIdentifier must be the project ID from the Harness URL, not the display name, and orgIdentifier is usually 'default'. 4) 'File already exists in GitHub': import from Git instead of creating the pipeline. 5) Cloud infrastructure asks for a credit card (no charge) or install a Docker Delegate.

Context: Most first-run Harness pipeline failures are identifier and infrastructure mismatches, not YAML syntax.