If you have been following this course in order, you have made it to the end of Learn HTML! You've learned a lot, from the basics of the language, through to many of the finer details.
Additional resources
The other courses on this site take a deeper look at some of the things you have already covered, and introduce other subjects needed in your life as a web developer:
In all of our courses we heavily link to MDN Web Docs, and the HTML section of the documentation is an excellent resource.