Today there are two methods for creating really simple sites. The first one is the old fashioned way, and it's stood the test of time; creating HTML documents that link to one another, organising them into a folder, and uploading the folder somewhere on the internet so that other people can browse it. You'll need knowledge of HTML at the very least to do this, and CSS knowledge is great too. Confused? There are quite a few HTMl guides on the internet. You could try W3Schools, Quackit, or even Dragonfly Cave for a good explainer on how to start writing web pages. In fact, I got started with Dragonfly Cave! I'm not going to bother making yet another html guide, so go and take a look at those links. Once you feel comfortable working with HTML and CSS, you can start writing pages for your website.
The second method is to use what is known as a static site generator. Static site generators take your normally written content - articles, blog posts, etc - as simple text files, and transform them into a complete website composed of HTML pages. Instead of you having to write the HTML markup yourself each time you create a webpage, a static site generator automates that process. They are a good option if you'd like to run a blog, but you can make any kind of site you like with them - including personal webpages or Pokemon fansites! The more willing you are to learn how to edit themes and use CSS, the further you can go. Keep in mind that this same power means they're a lot more work to set up than Wordpress or Blogger.
My site is a Neocities site! They're pretty much the best free web host for static sites, created with the purpose of providing a space for the revival of wacky personal sites from the nascent internet. That is to say, it's Geocities for the modern age! Comes with a command-line API for easy file uploads. Very reliable in terms of customer support and so on.
Their free plan gives you 100GB bandwidth per month, can link to a Github repository, and supports continuous deployment. You can also use the static site generator Hugo via their web-based command line, which is good for blogs (and lots of other sites too).
Another service similar to Netlify, with 100GB bandwidth per month on their free plan; however, it only supports static sites. It can link to Git for continuous deployment. If you want to create a blog or use a static site generator, you can use Jekyll, Gatsby or Hugo.
Github offers a free website for each Github project you have, along with one extra for personal use. You can manage your website's files and resources via a Github repository. It also supports blogging with the static site generator Jekyll.
The only free host on this list which allows server-side code. Offers a free plan with 3GB bandwidth, 300MB disk space and access to MySQL, CPanel, and PHP (along with a bunch of other server-side technologies). However, if you don't regularly log in and/or update your website it will be archived and unaccessible to viewers.
Most modern websites have some form of user interaction. This typically consists of comments on each page, or a chatroom/forum for regular readers of the site to hang out in. Below are some free services you can embed into your site.
A free comments system for static sites which uses Github/Gitlab to store and process comments. You get to host your own comments system, essentially, though it's more work than something like Disqus.
Another popular comments system which has a free plan. Chances are you have seen or used Disqus before, but it tends to load slowly and has ads on its free version.
Like Disqus, it is a comments system hosted by another company, but this has the bonus of not displaying ads on its free version!
A shoutbox - essentially, a live chat which you can embed into your site for users to fool around in. It only saves the last 100 or so comments, with anything past that being deleted. My site's chat is a Cbox!
An email contact form that works with static sites (ie. doesn't need server side code on your part). Has a free plan.