Nothing to start. Go to copilot.com, or open the Copilot app on a Windows 11 PC, where Microsoft says it is typically installed by default. You can chat without an account.
Signing in with a free personal Microsoft, Apple or Google account is optional, but Microsoft says it unlocks chat history, longer conversations, more image creation and longer voice sessions.
The free tier is not a trial that expires but a working assistant with ceilings: ordinary chat keeps going, while image generation, voice and the heaviest thinking run down and refill.
Most beginners never pay. You would pay for two things — Copilot inside the Word, Excel and PowerPoint desktop apps, and Copilot Vision, which lets it look at your screen — both currently needing a paid Microsoft 365 Personal, Family or Premium subscription. Businesses pay for a separate per-user add-on; see current plans on the tool page.