iCloud backup
there are 3 different iPhone back ups 2 are backups from September and one is my current phone . Is it safe to delete the 2 with erasing old information ?
iPhone 11, iOS 14
Deleting a backup will not delete any data on your phone.
Also, if the backups from September are from a previous phone and you have already set up your new phone and have all of the data on your new phone, there isn't any reason not to delete the old backups and it will free up some space on iCloud.