Hello @siljith
The warning about newer release of Amazon Linux is non-blocking. I get this too but the execution of the command continues without a problem.
It is strange that you are getting two VPCs with the name of
de-c3w2a1. If you continue to have this problem even after a fresh lab restart and you are sure that you are selecting all the correct options when creating the Cloud9 environment, please fill out the lab refresh form to see if that helps.