There are quite a few collections of free html and css templates. I found this one using "free css templates" on a search engine. [1] I don't personally use these and instead just use a very simple layout for my blog site that was from an example with a vulgar name sometimes linked here. "Thebest#$@#(%^website" so I won't link to it but you can probably find them.
[1] - https://www.free-css.com/