I have trouble starting my vehicle.

Get the MAF sensor (you might be able to just clean it) and camshaft sensor codes fixed first as they might be causing the other codes.
I would find a good repair shop that is good at diagnostics. These codes need to be diagnosed. You might just have a bad camshaft sensor, but to be sure you should have it diagnosed.

I could not find PO0105 but I would ignore that code for now and focus on the other codes. Cylinder #3 misfire could be related to the camshaft code. Check the timin g belt to verify it has not jumped? As for the Oxygen sensor code your most likely problem will be an exhaust leak. Check ALL EXHAUST NUTS. They come loose and you could already be missing a bolt or 2? Have the exhaust leak repaired and MAKE SURE TO HAVE THE FUEL TRIM ADAPTATIONS RESET!!!! OR THE OXYGEN SENSOR CODE COULD COME BACK ON? Now if the stalling is an issue and you have trouble starting back up then you could have an issue with the mass air flow sensor but like I mentioned before, leave that code for last since the oxygen sensor code and exhaust leak could be causing that code to set falsely? Good luck and leep us posted.

Thanks for the response.
I took the car in to Volvo and they replaced the fuel pressure regulator. They reset the code and the check engine light stayed off. They also drove it for 23 miles and had no stalls so I picked it up. When I went to pick it up the check engine light was on again. It started OK and seemed to be running better so I just took the car to do the rest of the repairs later. Now, yesterday, the car stalled on me again. I haven't had a chance to check the exhaust leak but I'll do that and then clean the MAF sensor to see if that fixes the problem. It also seems like the transmission is giving me problems.