I agree with the consensus of the posters that it is not easy to find cash flowing properties in San Diego but my area of investment in San Diego typically cash flows today (just not as much as I want it to in order to invest).
I personally am looking for good ARV (80% ARV) that either cash flows or comes very close to cash flowing in my chosen investment area and those properties are hard to find.
If I was younger and just starting I would look to house hack a quad plex using an HOA loan in an area where the property would at least be close to cash flowing and I would be OK living at. HOA loans typically require less capital. You would learn a lot and the other tenants would be helping you build equity via their rent payments that you would be applying to the mortgage payment. Any appreciation would be additional equity gain. My first step would be to determine the areas I would be willing to live for the next 3 to 5 years. Then start looking for that quad (second best would be a triplex) that comes close to positive cash flow.
In 3 to 5 years maybe do it again to a nicer area/property or use the equity to buy a SFR and just property manage the initial property. The equity would provide you many choices.
As for whether it is a good time: I think San Diego property is in constrained on virtually every side (Ocean, Mexico, Camp Pendleton, too hostile as get to Jamul and beyond) and therefore has a limited supply. Climate wise it is the best in the US. Because of this I do not believe that it has reached its zenith but I do expect the appreciation to be much slower than the last 5 years. I would not expect the appreciation to offset a huge negative cash flow. Add in the historically low interest rates. So I think today is a better time to purchase than next year (or any time in the next few years) but worse than any time in the last 5 or 6 years.
When you do you the numbers on a property do not forget Cap expense. A lot of new investors underestimate cap expense. Either use a spreadsheet with expected costs and lifespans or get some help from an experienced investor as San Diego cap expense is significant.
Good luck