You can give titles to the other admins and your staff/teachers by following these steps. 

• Click on the community in the left menu 
• Click Manage icon 
• Click Staff 
• Click on the name of a staff member
• Click Change Role icon show below
• Click Next

PS: The same steps can be followed to give titles to other admins in the class, however, you need to do it from the Manage screen of your class page.