Can I turn off the invitation emails to parents & students

Yes you can,  here is how its done .

• Step 1 - From you admin console login to your School account and select settings
• Step 2 - Turn off the allow parent/student invite
• Step 3 - Most important , please scroll down and click Save button 

When you access Students , you will specially see a note that parent and student involvement is off and no invites will be sent