Do you know anything about the differences between vector and raster graphics? There is no automatic or simple solution to convert from raster to vector format. There is no generally applicable solution: different images will need different solutions, and often quite a bit of hand-adjustment too. Your two main options would be to:
- Use a vector graphics tool (e.g. Inkscape) then use its inbuilt tools to convert the PNG image. You will find lots of advice and tutorials on the internet.
- Use an online tool to do the conversion, which is brainless but gives unpredictable results over which you have little control.