I am installing a drop lamp in the dining room. The insulated 3 wires from the lamp are not labeled or colored. The insulated wire is labeled AWM 20242. How do I know which wire from the lamp should connect to the white, black and ground wire coming from the ceiling?

The wires have no color, does that mean clear? Usually bare or green is ground, white for neutral and a black being the live conductor on most/many lamps.
If clear, usually the smooth is hot, ridges is usually neutral, and a bare or green for ground.
If none of the above helps, use a meter or continuity tester, and with lamp unplugged, identify the center of the bulb socket with black tape, (be sure any switch on the droplight is on), Identify the shell of the socket wire with white tape.
And check for continuity between the 3rd wire and the body of the lamp, identify this wire with green tape.
Good Luck. Have a good New Year.