why isnt my imessage activating

To send and receive MMS messages on your iPhone, verify that your wireless carrier supports MMS².

Ensure that MMS Messaging is turned on in Settings > Messages.

Verify that your phone is able to access cellular data.

• Some carriers allow you to edit your APN (Access Point Name), which may prevent MMS from working.
• If you are roaming outside your calling area, make sure you have Data Roaming turned on in Settings > General > Network to send or receive MMS content.
• While on a phone call, you will be unable to send or receive MMS messages when using an EDGE, GPRS, or any CDMA cellular data network. After the phone call ends, you will receive any incoming messages. If you tried to send an MMS message, you may need to send it again.

SMS sends only text.

You have to turn on iMessage in iPhone settings.

Go to Settings>Messages>Send and Receive and check if there is a tick mark beside your phone number. If not turn iMessage OFF wait a few seconds and turn it back ON. Wait for activation. If works you have to see the tick mark besides your phone number.