Messuring DC-Motor parameters
Use ohmmeter to determine the resistance. Or lock the rotor, apply certain voltage level and measure the current.
With AC voltage you can measure phase angle between current and voltage, thus determine the inductance.
Spin the motor with some auxiliary motor coupled to a shaft, measure the speed and the induced voltage. Determine Ke.
Derive the Km from Ke. If they are in SI units [Vs/rad],[Nm/A], then they are the same value.
You'd need to know the torque and acceleration to derive the moment of inertia. Or you can wind a tiny rope on the shaft and apply a mass, then measure the time and speed to determine the acceleration - the torque is T=mgR  .