By Default, there is an All Team Members chat created for your team. As the name indicates, this is a chat for all players, parents, coaches, etc that are on the roster.
To create a new chat for groups or to an individual:
1. Go to the Chat Section of the App
2. Click the '+' icon to add a chat
3. Select the recipients of the chat
4. Name your group and press 'Create'
Your new group will now be visible under the chat section