First up congrats on the new camera! I have the same camera and love it... I mostly use a single lens all of the time, the Sony 28mm FE f/2. It's relatively inexpensive, fast and focuses quickly. It's wide enough for doing some moderate landscape but also great for taking pictures of animals/people.
If you want a wider lens dedicated for landscape, the Samyang 12mm f/2 is amazing, light and cheap - only thing is you have to focus manually, but with the zoom assist and focus peaking that is really easy on most mirrorless cameras these days.
Both lenses are really sharp as well, which is really nice.
Some examples of the Sony 28mm:
Liverpool by
Matt Skinner, on Flickr
Amsterdam by
Matt Skinner, on Flickr
Jersey by
Matt Skinner, on Flickr
And one of the Samyang 12mm:
Corfu Town by
Matt Skinner, on Flickr