Here's what each message status indicates:
Sending
Sent
Delivered
Read
My message is stuck as 
Sending, spinning or paused. What do I do?
Signal uses your phone's internet connection for all private communication. The most common reason why you can't send messages is that you are not connected to the internet or have restricted Signal's internet access.
- Confirm you are connected to the internet.
- Re-enable permissions and settings on your phone.
- Disable or modify settings for your third-party app, VPN, or firewall that is limiting Signal's connection to the internet.
- Scroll up through the conversation to see if there is a large attachment that is trying to send and delete the message.
- Complete any captchas that appear.
- Contact us and tell us what the message status is.