I don't think that there is anyplace to shoot outdoors in the Conejo Valley. It ois definately illegal to shoot in any of the city and county owned green space, and the SM NRA is out of bounds.
I used to drive into Los Padres National Forest. They closed the Condor Santuary to shooting a couple of years ago (above Fillmore) a couple of years ago, but you can shoot in the NF off of Hwy 33 - except for fire season. Cherry Creek is a good spot, but the gate is usually closed and locked and I don't want to hoof all my stuff in.
Lately I have been shooting at Wes Thompson's range above Piru. It's abiut 40 minutes from Newbury Park, but it's convenient and relatively inexpensive. There's also great cowbot action shooting (SASS & Western 3 Gun) up the road a little bit.
BD