That depends. Would you rather take the time to learn on your own or get back on your bike sooner? Keep in mind that if your LBS is like mine back when I didn't know much about fixing a bike, they won't make the wheel any better than you have. Mine deemed a rear wheel of mine unfixable way back when. Luckily I kept it because after I learned a few things about wheel building, I went back and fixed it easily (the aluminum nipples just needed lubricating before attempting to true and tension the wheel).

Now that the pinging has presumably stopped, what you really need to do is to verify that all spokes have even tension and that the wheel is true after adjusting the tension. The spoke that came loose did so because it was severely under-tensioned from the factory and so it's quite likely that other spokes are, too. I bought a simple Park Tool tension gauge and it has served me well for my wheel building endeavors. A tension gauge will quickly allow you to see the tension on the spoke though you can also pluck the spokes and listen for a specific note (I'm a mechanical not musical guy so I never even bothered trying this). Of course, you can also roughly gauge tension simply by squeezing adjacent spokes and feeling for deflection. Squeezing really tightly will also remove any additional spoke wind-up.

This last method would be good enough to get by for a while allowing you to pick up some tools and do some reading before truly diving into your wheel to set the tension straight. When you do go full bore into it, you may want to save yourself some aggravation and completely loosen all the spokes to start. You may also want to have a spare wheel on hand in case you run into some issues :-)