Understanding metal oxide semiconductor gas sensors' datasheet.
How do i measure RL and VRL?


They're noted on page 2 of the datasheet you linked.  RL is your 10k resistor.  VRL is the voltage developed across it.  VC is the sensor's supply voltage (note that the heater (VH) must be 5V +/-5%, but VC can be up to 15V max per the datasheet).




  Furthermore, in order to obtain Ro, do i need to run a control, and
  record RL in clean air and assign Ro to that value?


The datasheet defines Ro as "Sensor resistance in clean air".  So if you require Ro, it would appear that you need a sensor exposed to clean air.  I'd suggest chatting with the manufacturer as to whether your application requires a) continuous operation of a clean air reference sensor, b) if it's just a one-time calibration step, or c) if it can be done empirically.