You have not said whether you are using Windows or Linux. You could start by creating a HTML file using a text editor. Then browse to that to see what it looks like. Some editors are WYSIWYG; you can see the formatted web page alongside the HTML, or something like that.
There are sites like the following, there are many others like these.
Using them you can try out HTML and see the results. If you want to keep something then you need to save it separately, such as copying and pasting into a file.
You can try the HTML Tutorial. Most of the pages have a sample you can use that actually shows what the result is, like the pages above. There are other courses in W3Schools Online Web Tutorials.
If you have a Google account (most everyone does) then you can create websites at Google Sites. That will not help much to learn how to create websites except some of the basics. At least you can create something quite quickly that way, for free. Be careful about other websites that will create a website for you, if they charge money for more advanced sites then it is best to not get started with them.
There are many more resources. If the preceding are too basic for you then it will help to be more clear about what you need help with.
