My 2c contribution: low-light shooting, even with a great low-light shooter like the K-x, simply takes practice. It's more demanding than shooting in full daylight and takes more work.
To acquire more experience, do stuff like take several window-shopping walks around town in the evening after dark with your camera (if it's safe to do so). Set the camera on P mode to start with and take lots of photos of different objects illuminated in shop windows, street lights and other kinds of poor light etc. Or take your camera into a local restaurant, cafe or bar at night and take photos. Then go home and review the results - what worked, what shutter speeds you could go down to whilst getting a good shake free image, how to deal with focussing under low-light etc etc. Repeat the process again until you become more confident, and know what works and what doesn't.
You can get quite good results with the kit lenses under low light, but as others have highlighted, fast glass helps tremendously. It's amazing where you can go with the K-x and something like the FA50 1.4.
A tripod is nice but not always practical. I rarely use one, except for birding with a telephoto, but even then not always. With good camera-holding, good bracing or support and careful shooting style, one can get away without using a tripod most times. Lots of objects around the place can also serve as impromptu tripods too - table tops, the back of chairs, signs, fence posts, someones shoulder
etc.