How can I activate iMessage on my new iPhone?

These helpful tips should sort you out;

1. Ensure you have sufficient data balance or Wi-Fi network.

2. Verify your time zone and set it correctly: Settings > General > Date and time

3. Turn off and restart iMessage It may take up to 24hours to activate. But if after 24hours the issue persists;

4. Be sure your device has the latest version of iOS

5. Try to send regular SMS whether local or international, if you can't, contact your Network provider to resolve your SMS issue. If you still can't activate your iMessage, please contact Apple support.