Be aware that your cell phone camera makes adjustments to get what it is programmed to do: get evenly exposed pictures. That programming often transforms a shot meant to show that it’s night to one that looks like day. You can avoid that by including more dark space around your subject. Learn to use the exposure tool. It’s easy. Frame your shot and then touch the brightest spot in your frame with your fingertip. An exposure tool (mine has a sun) will come onto the screen. Your camera will expose for the spot you have chosen, and the rest of the photo will be dark. This tool is great to use, not only for night shooting, but anytime you want to get the best exposure for a particular part of your photo.
Shoot up at streetlights, windows, buildings, traffic lights. I love shooting store windows, even restaurants filled with people at night. You will find your night pictures to be grainier and more pixelated than photos taken in higher light levels. It will always be the case. For that reason, many people only shoot in bright light and from their perspective, the best shooting conditions. Not me. Shoot what you like and have fun with it. Not every picture has to be published in National Geographic. By the way, I recently talked with with a National Geographic photographer who told me he is shooting almost all his assignments exclusively with his cell phone. If you keep practicing, the photographs you take with your cell phone can be that good.