Great Free Resources to learn Web Development-
https://www.appbrewery.co/p/web-development-course-resources/
https://developer.mozilla.org/en-US/
For HTML-
https://www.w3schools.com/html/
https://web.stanford.edu/group/csp/cs21/htmlcheatsheet.pdf
For Responsive CSS-
https://courses.kevinpowell.co/courses/conquering-responsive-layouts
For JavaScript-
https://javascript.info/
If you want a good paid course, this is what I find the best-
https://www.udemy.com/share/1013gG3@VEQQ_Di3RqzhPYhYsYYCHhSYxqfqI-cdepgUG0FOu9naSSj_q-HLDGAGvu9AEHpCJQ==/