You will need to download a community launcher (such as the one from Battlefield2142.co ) to find active servers and manage patches.
Because physical copies exist (DVD-ROM boxes), some sellers list "New" CD keys on eBay or Amazon. However, nearly all of these keys have been used, banned, or are duplicated. A single CD key from 2006 could only be used on one EA account. Any key sold today for $5 is almost certainly a fake or a used key that will not work. Battlefield 2142 Deluxe Edition Cd Key