snapbridge – Nikon D5600 Photos come out blurry when zoomed

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 SnapBridge app. I will also give my usual settings if needed.

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?
Picture from iPhone

Picture from Nikon D5600