California sells thousands of OTC deer tags, and bear tags are also OTC.
I got a great bear and a 4x3 deer with OTC tags earlier this season, though I paid an outfitter to get access to private land.
Without access to private land or intimate knowledge of the local areas the odds of a successful harvest aren't great, but the public lands in the Sierra Nevada Mountain range are a gorgeous place to take your rifle for a hike in!
The male mule deer on public land in Cali are almost entirely nocturnal during hunting season, you won't see them except right around sunrise or sunset as a general rule unless they get flushed out from their beds.
Just bring a bolt action or lever action rifle to avoid all the ever-changing gun laws regarding semi autos there.
And you must bring your own non-lead hunting ammo, you cannot buy ammo in California as a non-resident, they require background checks for ammo purchasers and if you aren't in their system they won't sell.
If you go to reddit.com, there is a subreddit for r/californiahunting that has a lot of info and lots of hunt reports, both successful and not. That subreddit is marked "NSFW" though so you may have to update your settings.