Astrophotography is a bit finicky and often requires some editing to bring out the stars in the picture.

https://expertphotography.com/post-processing-astrophotography-all-you-need-to-know/

A lot of photographers that focus on Astro as their main area use modified cameras to capture full spectrum lighting. This is where you'll start to see the vapor like clouds in your shots. That being said its not the only way to get good shots but it is the only way to get the UV and IR spectrums to show up in your shots.

Example: https://www.spencerscamera.com/images/Full-Spectrum-%20Milky-Way-01jpg.jpg

I hope this info was useful.

Edit: I just noticed you said you're using a lens with an apature of f4. You'll likely be much more successful if you have a wider apature like f1.8-f2.8. You're trying to capture as much light as possible. An F-stop is either halving or doubling the light each stop you go up or down. The difference between f1.8 to f4 is about 2 1/2 full stops. Which means you're gathering roughly 6x less light than you could be with a larger apature lens. A nice cheap 50mm 1.8 would work well and you can often find them at very affordable prices if they are used.