These are some of the best resources I found, read them in the sequential order.
CodeCademy’s HTML/CSS track :- Hands down, it is the best way anyone could get comfortable with the basic structure and syntices.
Shay Howe’s Tutorials :- Though this may come as a little overwhelming, this is by far the best series for diving deeper into front end development. Go slow, take your time.
At this stage you are ready to create some cool project of yours, go design a webpage, imitate one!