The 25 isn't a bad portrait lens (it's equivalent to the "nifty 50" on 35mm) but it's not going to be ideal for landscape. Fast, wide, OIS lenses aren't cheap. For landscape you'll probably be using a monopoly or tripod, consider a manual prime or a used Panny pancake.

Panasonic Lumix 14mm f/2.5 G Aspherical Lens for Micro Four Thirds Interchangeable Lens Cameras (Discontinued by Manufacturer) https://www.amazon.com/dp/B0043VE29C/ref=cm_sw_r_cp_apa_L1o-BbAE26014

Based on advice from these forums, I went for body only plus these lenses:
Panasonic 14-140mm

https://www.bhphotovideo.com/c/product/1469487-REG/panasonic_h_fsa14140_lumix_g_vario_14_140mm.html

Panasonic 14mm f2.5

https://www.amazon.com/Panasonic-Aspherical-Interchangeable-Discontinued-Manufacturer/dp/B0043VE29C

I'm very happy with both of them, primarily using them for video. the 14-140 does everything I need, especially for home studio needs. The 14mm prime is just nice to make the camera super compact, and I intend to use it more for street/from the hip shooting. If I could only keep one, I would keep the 14-140. The dual image stabilization between the lens and body is fantastic, and means you don't really have to carry a tripod or gimbal.

I bought everything used. Only gripe I have thus far is that the camera battery life isn't great for video, so I'll probably get an AC adapter system for it.