I am using a simple Jekyll theme minimal-mistakes[0] which I customized to suit my needs.
I'm hosting my blog[1] on GitHub Pages, the repo[2] is public so you can take a look and fork it if you find it interesting.
The setup is really simple, straightforward, and no-cost.
[0] - https://github.com/mmistakes/minimal-mistakes
[1] - https://www.vladsiv.com/