In addition to what FF is saying, this color wheel may help for you to use colors that compliment each other: https://color.adobe.com but for a first vector, it's a great start! I esp love the orange bg and how the buildings blend into the sky
I can't see your image, but Inkscape is a free vector program that can trace a vector image from a bitmap (also a pretty full-featured drawing program!). You can download and try playing with it and see if it meets your needs.
ok, so I have an SVG version of the image, I just uploaded a png.
I used vectr.
https://vectr.com/bestbluepenguin/a7nInTTJ7.svg?width=500&height=1000&select=a7nInTTJ7page0