Tb, learning to hunt southern Ca with any regular success can be a monumental undertaking. As previously stated, we have some pretty dismal herd numbers along with very low buck to doe ratios. So as was said, finding deer can be problematic for a variety of reasons, let alone trying to find a buck, and a legal one on top of that. You are going to find a stark difference between hunting most other places, as So Ca is generally a dry habitat. Meaning it is also noisy, crunchy, loud... and fly, mosquito, nat, bee and overall, bug infested; of course that can also be an advantage if you know how to use it.
We have been in an extreme drought that has spanned several decades, with a spattering of average and average+ years thrown in there. But certainly not enough to actually get us out of the drought., For most states that would mean that the mule deer are expanding their range and building their population. Unfortunately that is not the case here in So Ca. Mainly, because we have a water availability issue. What I mean is that we have very large swaths of land with feed that will sustain the deer, but there is no water in reasonable distance or abundance. In short, we have large areas of land that are under or unutilized. What that means is that you can easily go without see deer (while doing all the right things) because you are simply in the wrong places.
Back in the day, I almost exclusively bow hunted the deer here in So Ca. And I can tell you from first hand experience, they can be exceptionally tough to hunt with consistent success, with a rifle or a bow. I was, and still am an exception. My bow hunting success came from scouting almost every day of the week. My strategy was to find the bedding areas of several bucks (multiple bedding areas per buck), and then literally cut a trail to withing a good shooting distance. I would do this while the bed was unoccupied only. Then just prior to the season, I would rake each trail, again while they were unoccupied. I took into account the predominant wind direction during the season.... I would also wait for the heat of the day to set in, because they do not want to expend energy unnecessarily. Meaning when it is hot, they tend to hold until the last minute. I would then move in, in slow motion, and almost always, the bucks would hold and allow me to get within shooting distance, and I'd release an arrow. I always filled my tags.
But, considering your situation here, my advice is that you start with rifle hunting. Grab yourself a general season tag. If you can afford to get both the gun and bow here, that general season tag for most local zones is also good for the archery season. You have a very steep learning curve ahead of you. Sure you will find much less pressure during bow season, but you first need to figure out where the right places to be are, which can take years here in So Ca.
Best of luck, and please, post your experiences, they will be highly valuable to many here in So Ca.