Stack Overflow is a website for Q&A on all things software development, including HTML. It is a great place to find answers to your questions
Tutorials Point is a website very similar to w3schools. Everything said about that site can apply here too.
Youtube is a website where you can find all sorts of videos. This includes videos about HTML, of which there are countless.
Google is the world's leading search engine. If none of the other sites helped you, search for your HTML questions here