I wish I could design actually good looking websites. It's not about css, my problem is that I just can't imagine what I would want it to look like. My brain do be very not creative.

Most of the time, it’s not about being creative or not, but knowing design principles and rules.

You can look around other websites of similar industry and get inspiration from that. Choose say your top 5 most liked design and build a catalogue of them for you to borrow ideas from for your next project.

I also have the same problem 😣

I too face the same problem. I feel I have an eye for "well" designed websites/apps. But I fail to create them myself.
I have come to realise that the best you can do is research in these cases. Look around at websites like dribbble, behance etc to find exciting designs. Combine that with basic laws of UX (https://lawsofux.com/) and you have yourselves a great design!

Go through designs that others have created. I've seen it's much more beneficial to break these designs down by usability and intent.

Borrow these principles first to create "unoriginal" designs. Eventually there'll be a stage where you have internalized the ideas and can create your own deviations.