If you click on your profile link in the top right corner of the community forum, it will take you to your profile page. There are options for editing your privacy and your preferences. Click on the edit Preferences option to turn off the email notifications for this Community.
You would have to ask a admin for the community forum to delete your account here. Usually it is easier to turn off the notifications and don't log in again.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.