Runway is not active ATC asigned to me

Hello, 

I go by VFR without a flight plane Location LOAV (Wind:  010 at 4 )

First i requested active runway and got correct runway 31, 

After it i requested taxi to active runway I  Got runway 08 (grass for verry small airplanes)

I am not a real life pilot, prorbably i do something wrong ?

Controller: Info_Tower (LOAV) 118,6

Pilot: <call signe> "say active runway"

Response: Runway 31 for arrival and departure

Pilot: <call signe> Request taxi to active runway

Response: taxi to runwax 08.... !