My gmail account is properly set up and shows a list of folders, Inbox, Drafts, etc. But it has an additional folder all [Google Mail] and in it I can see All Mail, Spam, etc. I want to disable it and disable the subscription to it so that it doesn't appear in the interface at all.
You can disable certain IMAP folders in GMail, including the All Mail folder, if you enable the Google Labs "Advanced IMAP Controls". From webmail:
Be warned that you lose functionality if you disable some of those folders, though. If you disable the spam folder, for example, then you can't train GMail's spam filter from Evolution, and disabling the "Trash" folder keeps you from being able to ever delete anything.
remove your account and follow this tutorial, If you want to get only new email!
if you set server type to IMAP in receiving email step it will download your whole emails to evolution but if you set it to POP it only download new emails you receive