I just sanded my hardwood floors with a sheet palm sander and hope to be ready for a dark stain. After a second run through of sanding, it still looks patchy. I tried to sand each board individually with the woods grain. The first run I went from 100 to 220 grit and the second time I transitioned 80-120-220. If I stain it right now will it look bad? Do I need to sand a third time? Any help to make my hardwoods look great is greatly appreciated! (There could be a very light layer of dust that settled on the ground after sanding and I should also mention this is my first attempt doing this!) Thank you in advance!

It looks like there is still finish on the floor which will need to be removed for a decent stain. Most floor mechanics only sand to 100 grit on an oak floor.
You can use a scrape with a file to help keep it sharp so you can draught shavings when you scrape to get to bare wood faster than using 100 grit with a small sander. After scraping you can hand sand with 80 with the grain grit to be ready for a stain. Broom up the dust or vacuum. Do a small sample in a corner to see how it looks.
It looks like you have a #1 common red oak floor. Is it top-nailed?

Thats not even close.