Measuring experimentally the poles parameters
It's a second order low pass filter so use a signal generator and oscilloscope and look for the magnitude peak and frequency where it occurs: -

The peak amplitude can be converted to zeta (\$\zeta\$) and zeta (aka the damping ratio)  relates to Q-factor as follows: -
$$Q = \dfrac{1}{2\zeta}$$
And you can plug \$\zeta\$ into the peaking frequency formula to find the natural resonant frequency (\$\omega_n\$). Then if you wanted, you could double check that at the natural resonant frequency, the amplitude of the sinewave is Q times bigger than it is at very low frequencies.