AlyssaBlue said:The leaves are really big for an oak that size!
When plants are young they are determined to survive. There is something called
phenotypic plasticity - either the roots, shoots or leaves are changeable depending on the environmental conditions.
An oak growing in the shade may well start out with larger leaves that will increase the amount of sunlight the plant can absorb. After the tree grows tall enough so that its head is up in the sun, the leaves grow 'normal' size because they have direct access to sunlight.
Good luck avoiding the poison ivy.