Agreed, if that is primary you have either collected too much wort if a kit, or a lot if that is what you were looking to get. That space will quickly fill and likely blow off if primary.
If so get a blow off tube on it ASAP.
If secondary it looks good.
Since fermentation creates co2 which is heavier than oxygen, too much headspace in primary is not really much of a concern.
After you have pitched the yeast you usually do not want to aerate any more. With most brews that would be bad, risking oxidation.