one question I would have like answered is this inflating universe happening at a sub atomic level ?
No is the quick answer.
Atoms are held together by the strong and weak nuclear forces and electromagnetism.
These forces are all very stong at distance on the scale of an atom. So an atom doesn’t “feel” the space inside it expanding
Even large scale structure in the universe such as galaxy are pretty well held together by gravity.
Back to the balloon analogy:
Imagine the universe is a balloon being blown up. Dots on the surface of the balloon move further apart as the balloon “inflates”
Now imagine that the ink in the dots likes to stick together (becuase of gravity). The dots move apart but don’t get any bigger as the balloon inflates.
So the expansion reallly just affects the empty space in the universe