@Douglas Watts, go to your created group. You see the "Group Message". When you click on that, it will go to everyone in your group. If you want to send an individual message to one person, find the person in your member list. click on their name and a box will pop up where you will be able to "Message" only them.
We hope that this answers your question.
I have followed the above guidance and the message has not shown up on my message page. I went into windows and removed the cookies and temp files. If a message does go out where should one look to see the message?
@Douglas Watts, you should be able to see your message and any responses in your Message box at the top of FamilySearch by clicking on the Message icon. Try going back to your group and send another message to them and make sure you click on the arrow after writing your message. You should now see your message after it has been sent in your message box while you are still on that page. When you go out of that page, for example, click on another page or go to a person page. Now up at the top you see where you get your messages. Click on that and you should see the message that you just sent. And if a message is sent back to you, there will be a red dot. This is where you will see the replies on that thread.
I hope this works for you.