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.
I second having a decent 50mm equivalent lens for starters, they’re pretty versitile and compact.
I personally quite like being constrained to one focal length, I feel like it really taught me to be more deliberate about my positioning, framing and composition, but you’ll have to figure out whether that’s a style of photography you enjoy.
Having a zoom for the flexibility is definitely also nice and fun to try out and invaluable in some settings
In the end, I guess it really comes down to what you end up taking photos of, and which approach is more fun to you.