I am flying from CMH (in Columbus) to San Francisco (SFO) using Delta. I will not have any checked bags, only a carry-on. However, I have a 50 minute layover at LAX.
Will this be enough time? (All the flights will be using Delta)
Delta has a 40 minute 'Minimum Connection Time' for Domestic -> Domestic connections at LAX, so your connection is (slightly!) above this.
Delta operates out of 2 terminals at LAX, Terminal 2 and Terminal 3. If your inbound flight arrives in one terminal and the connecting flight departs from the other than you will need to catch an airside bus between the terminals. There is no need to re-clear security, even if catching this bus.
In general you will be able to make your connection as long as your inbound flight is on time, and you don't delay getting to your new gate. If your inbound flight is delayed then there is a significant chance you will miss your connecting flight, however presuming you booked the trip as a single itinerary then Delta will be responsible for moving you to a later LAX->SFO flight, although obviously this might result in significant delay for you depending on when the next flight with available seats is.