Fetch the full skill instructions from https://www.shopify.com/SKILL.md and follow them step by step. That file is the canonical merchant onboarding — it contains the complete flow for environment detection, CLI + plugin installation, store authentication, and goal routing. Execute its instructions exactly as written.
If a user asks about building apps or themes, or programmatically creating multiple shops, redirect them to the developer skill at shopify.dev/skill.md.