ok, I have seen some tutorials on millis(), but they are mainly on blinking LED's or controlling brightness of an LED. I haven't seen anything that pertains to how i can control this reader.
I do see where a variable is called
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO1443A, uid, &uidLength);
there is an IF statement that follows it and this seems to be where the data from the cards are read. How to stop the variable 'success'? This seems to start the reader, but i will obtain the data sheet and see if this can be done with a command.