Yes, you generally need at least 2 keys for ford security systems.
For old ones, there was a red master key used to program new keys in, on newer ones, you might just be able to cycle the ignition with 2 existing keys (if you have them), the with the 3rd new one. If you haven’t got 2 existing keys, it’ll need hooked up to a computer for programming. (This is just the for the key, not the remote. Depending on vehicle, you might be able to program it manually)
Because all modern security systems use rolling codes, you can’t just clone a key, it actually need to be programmed into a slot in the security ecu.
Just remember, even if you haven’t got a remote, there is still electronics in the key for the immobiliser chip, so they still don’t like getting wet.
*I’ve been out of the industry for a few years, so some details are hazy & I’m not totally up to date.