I'd agree with hamidreza nikoonia about using a frontend css/js framework. They're a great way to take care of the frustrating parts of making a site since most are mobile friendly/responsive out of the box. Additionally, they are easy to understand and learn through their use of repeating patterns. With that out of the way, then you can focus on making the site beautiful.
But, what IS a beautiful and stunning website? My guess is that you have some sites in mind that you like. A great exercise for you would be to look at those sites and think about what it is that you like about them. Write it down if you have to.
Is it the photography? Great photography makes a world of difference. Is it the clean lines or the use of white-space? A sense of 'clean and crisp'? Is it the font or the way that the site just seems...'right' when you use it?
Ask yourself WHAT you like about these sites. Then, see if you can recreate the feel of it. Pay attention to things like shadows, heading sizes, colors. Remember "less is more" and don't try to crowbar too much in.
Over time, you'll get better. Over time, you'll be able to look at a site and immediately see what they did right and what they did wrong.