Project Question: Standards and Tags

I’ll admit, I’ve been sitting on the first project (tribute page) for a long time. I made one that was pretty okay, but then I started interning with a programmer who kept pushing me to change it with iframes and other PHP-driven items, but that didn’t work out, and I didn’t really like the results. So I re-did the page, and checked with a friend, but she was concerned about FCC’s tags requirements, mentioning that it looked like you are utilizing HTML4 vs HTML5.

So, all this is a bit confusing, and I wanted to know - what standards are we working with here, and if the parameters require tags, then tags it is. Should I submit it for analysis before final submission? Also, any ideas on how best to host it, or should I leave it as an HTML/CSS file folder?

Thank you for any advice. Much appreciated