To figure out the voltage drop, you can measure across the diode using the diode setting on the multimeter. Alternately, you can power up the LED in a circuit, and measure the voltage across it using the voltage setting. To measure the current, set up the circuit again (pick a 220 ohm - 1K resistor) and then us the multimeter to measure the current flowing across the LED. Alternately, if you really need to know precisely. Buy a new one that has a datasheet that specifies these details for you.