fresh install of WP, into pre-made HTML page? new here, possible?

Just installed a fresh copy of wordpress, but I would like to embed posts into an iframe of 800×1200 (modifiable). No clue where to go from here. I’m looking around the admin portal of WP, and I don’t see much about auto embedding, and from what I’m reading, it’s made for PHP (but there has to be a way to utilize in HTML…?)

I’m pretty dang new here, so… you know… dumb it down (if possible, I’ll try to climb the ladder in the mean time).