Now that you've got the bike, get a good lock for it!

I like the ABUS link locks like the Bordo 6000. If you want to be super secure you can get a cable for the front tire. Make sure any accessories (lights) are quick-release and come off every time you leave it at a public bike rack. It only takes a second to un-do them, and if you don't, someone else will.

A good lock will cost more than your bike. It's insurance against buying another bike, and will be cheaper in the long run, I've been using my ABUS lock for 10 years. It doesn't need upgrading when I upgrade my bikes!

edit: That's totally a score!
Look out for the brake levers, they're meant for drop bars, and putting them on flat bars like that means they were probably bent out so that they'd have enough travel. Either that or they don't have enough travel, which could be a safety issue. Take some close-up shots of the levers, and of the brakes when relaxed, just snugged to the rim, and clenched. Ideally the cable and housing will run out of flex before the lever hits the grip.