This is what one of my renders look like for example. https://imgur.com/LJ6nBNE

I guess the main problem is the samples. I have a i5 9gen and a 1050ti and the most long render I made is ... like 10 minutes, because of the amount of bricks I had for an animation.
Try to use de optix render denoising, and try, I don't know, like 140 render samples. And try the simplify option to see if that makes the rendering faster. And obviously, if you are trying to make a 4k render thats gonna take a really long time.
Start small, and then try to increase the numbers until you find a good quallity render in the in the shortest possible time, hope this helps you

another thing: find a tutorial to use the denoise node in compositing, is usually faster but not always looks good. In my case didn't work. The optix denoiser is much more accurate than the compositing node
And obviously, setup in edit > preferences the system opcion to use the graphic card, and try the optix option. My 1050 doesn't work with optix 😕 but with the 1070 should work, and is way much faster than CUDA