Can’t go wrong with the Lumix 25mm f1.7. It’s less than $200 and produces some brilliant images. M43 cameras have cropped sensors so it’s effectively 2x the focal distance, so that’s roughly the same as a 50mm on full frame.
For something a bit more flexible, a zoom is a good thing to have. The 14-150mm gives you lots of range, at the cost of lower max aperture (f4 iirc) and a bit of sharpness.
Down the road you might want a fast zoom, something like the 12-40 f2.8. It’s a bit more expensive, but absolutely gorgeous.
Good luck!!
Great pic!