Hello... I am trying to edit the floating distance between the weapon and the armor - I am trying to get the weapon closer to armor so it wont float.
So I am working on Steel Plate Armor. How do I do that?

It sounds like you might benefit from a look through the Creation Kit wiki, but very quickly it's the "Weapon Adjust" field on the armour addon you're after. So for the Steel Plate armour you'd be after the NordPlateCuirassAA item. It's near the top of that addon window.

It's not actually about the armor, it's the body skeleton. There are particular bones for back weapon, side weapon, quiver, mace, etc. You'd have to modify those to pull weapons in closer to the body.