You should always check your pages online by going to:
http://terpconnect.umd.edu/~USERNAME/INST671/hw1
Where you put in your own username and the correct homework name. If your page doesn't look right online, it will not look right to me. Furthermore, I suggest you check it from your phone or a different computer just to be sure everything is in order.
Your main page should ALWAYS be called index.html.
You may not ever use spaces in your file names. This is bad practice and often breaks things.