sharpness – Why are my new camera’s photos coming out blurrier than my iPhone’s when I look at them zoomed in?

I am a beginner at photography and recently got a camera (Nikon D5600). I watched a few videos on how to use it but I am still finding it difficult to operate. I have several questions but the main one is how to make pictures sharper?

I have an iPhone X which takes better pictures, when I zoom in I can see the image clearly, however when I zoom in on a photo with my camera, everything is kind of blurry. The photos I’m using as comparison are the ones from the SnapBridge app.

Does anyone have any tips on how to learn the best way to take pictures or how to at least make my pictures a higher resolution?

This is the image from my iPhone:

Picture from iPhone

This is the image from my D5600 and 18-55 kit lens @28mm:

Settings:
M mode, ISO 800, 1/200s, f/13, shooting RAW+jpeg.

Picture from Nikon D5600