If you can get a healthy positive cash flow on the property (rent would exceed PITI + maint and give you a margin on top of that), and you have a good loan on it, I would keep it. And I would manage it yourself (it is not that hard, just pick up NOLO press landlording in CA and put it on Craigslist). If it’s in a good area you can attract a good tenant, just read up on screening tenants thoroughly (credit check, paytsubs, call prior landlords, call employer, eviction check, etc…). Where else will you get a decent return on your 20% down payment cash? You will also get to depreciate the property and write it off your taxes.
To me you can mitigate risk as a landlord hugely by screening tenants well.
If you would have a negative cash flow (PITI + maintenance would exceed rent)…SELL IT!!!