More information would be helpful.
Screen shot of error messge are always helpful in situations like this.
C4D Lite (which is the version installed for free with AE) needs to be launched via AE the first time you try and use it. This is because the license for C4D Lite is provided via AE. The first time you try to open it you shoudl recieve a screen to sign in with a Maxon ID (this is different than your Creative Cloud ID) . Once signed in it should give you a walk through on licensing the C4D Lite app