Newbie

I just bought a 2003 base model Boxster with about 81k. I am brand new to Porsche, and have a lot of questions. I'm reading the owners manual, but what I need to ask you guys is not in there. Bought it from a used car dealer, so previous owner information is not easy to come by.
I noticed that the left headlamp (an HID unit) comes on but flickers. When I switch to hi beam, it also comes on and after a very short time goes out. The fog lamp appears to remain on, though. Can it be the bulb, or is it something else? Switch, bad ground, etc. The right side lamp works perfectly. Also, there is an electronic box mounted in the front trunk. What is that? The car had no reported accidents, and looked reasonably well cared for by the previous owner (I think he put about 60K on it).
BTW, how much is a new key? I have two originals, and they work the door and ignition, but the electronics don't work on one, and are missing on the other. Can a good locksmith program the key?
I would appreciate some good guidance.
Thanks,
Steve