yeah, a few things you can do to get better stuff with long exposure times –
1. make a lot of exposures – one will always be better than the rest. even when handholding, if you take a bunch, there’s usually one that is sharp enough.
2. be careful pushing the button – tapping the phone is going to jiggle it, blurring your photo. if you can use a timer, so it takes the photo 2 seconds after you push the button, that helps a lot.
for good subjects at night like that, look for cool colors in lights, things that are moving and will leave trails (like headlights). and really, some of the best times are after sunset when the sky still has a little bit of color but is going dark.
you can really great examples on dcphoto110’s profile page: https://photos.fovi8.com/author/dcphoto110/