I understand your concerns with not being able to send pictures in a text.
First verify that your account is in good standing and that your service is active. You may need to call your service provider. Make sure you have an active data connection to your carrier and temporarily disable Wi-Fi.
Clear your messaging app cache:
Open settings and tap apps
tap messages and then storage and tap clear cache
Restart your device
Inspect your Sim Card for damage. Contact your carrier if you need help testing your SIM or ordering a replacement.
If you are still having issue after performing the troubleshooting steps we recommend having a Samsung certified technician take a look at your device:
