2008 Toyota Prius Fails Engine Start-Up Check

Please help? I changed spark plugs and coils on my Toyota Prius 2008. Started and engine was running smoothly. Then I wanted to shut of check engine light and disconnected one of the plugs next to the starter battery. After that when I'm starting my car engine runs for few seconds and then shuts down. And have warning signals on my dashboard. If anybody knows what could be the issue please let me know thanks