how to dress up my site?

There isn’t one ……
You need to tackle 2 issues:
1 – Layout
For this, do you want a 2-column or 3-column blog ?
https://www.atthe404.com/trident/
https://www.atthe404.com/wordpress/
2 – Styling
https://www.mfr.f2s.com/1css/
https://www.mfr.f2s.com/graphicalcss/
will give you some broad ideas… very broad with the first ??

I agree. atthe404 is the way to go. I attempted to work with some styles I found that were contest winners an another site They were nice, however, I had one problem after another while attempting to customize them. I switched to the Gemini layout and it is terrific!
I’m very new to WP and css, so this was the answer for me.
Martin