I also have just a phone cam, but I try to make the best out of it. Definitely use your camera's raw file format if it offers it, then you can use tools like Darktable or RawTherapee (or the proprietary expensive stuff like Adobe Lightroom) to tune the colors etc much better.

For dark shots like this, just use longer exposure, and try to fix your phone somehow as to not shake it, in order to avoid blurring.