I believe there are ways to get HTTPS without paying the extortionate rates for an SSL certificate (e.g.
Let's Encrypt ), but other than that I know nothing about such things.
I can now add a bit more info.
One of my winter projects is to set up a simple static (old school like dave-cushman.net) website. Because it is static there are quite a few cheap if not free options. If anybody wants to do similar, the following will give you a secure https address:
If you want a custom domain name (web address) then you probably do have to pay at some point for that, but there are deals to be had like first year free on a multi year sign up, or first year for £1.20 if you just want to commit for a single year. The usual price is in the £15 - £18 range per year. Shop around for the best deal. Don't pay extra for SSL as this is provided for free by the site hosting service.
If you want absolutely no cost, then GitHub pages maybe okay for you. It has to be a website for a non commercial project. The web address would be "yourname.github.io". It's supposed to be used with the Jekyll static site generator (fancy blogging sites with themes), but this can easily be bypassed so you can use it to host standard html files. For it to be free you also have to use a public repository, but that is no big deal since your website is public anyway.
Other hosting options include netlify, vercel and kinsta. All provide free static hosting as long as you stay within limits, for example, serve less than 100GB a month. These can be used for commercial purposes. You can upload a zip of html files to netlifty, the others I think need to be linked to something like GitHub. This time you can use a private repository. To the non techie the GitHub instructions can at first appear intimidating, but you can do it all from the GitHub web page without looking at fancy commands.
A custom domain that you've purchased separately can be used with the free hosting services provided by GitHub pages, netlifty, vercel and kinsta.