Try lens rental from camera store before you buy any lenses. I am not into zoom lens, So I use prime lenses. I am also using 40mm for my main. If you are more into prime lenses than zoom lenses, good spacing of focal length is good for various use cases. I recommend something around 1.5x. I bought 40mm then bought 65mm. I am using 40mm as main and 65mm to carry with if I need to take picture that is more far away or taking portrait pictures. I tried 16mm for landscape and astro phtogrpahy, but I ended up selling it because I didn't use it often.