Students' PO box #s will not be assigned until around August 1st. Once you know the PO Box, you could ship the boxes to the campus Post Office and pick them up when you arrive, with the caveat that a lot of people ship things at the start of school, so there could be a delay in being reunited with boxes (so you would want to pack those things your student needs immediately in luggage you take on the plane).
Some places offer the ability to buy items onsite but pick them up at a different location. Bed Bath and Beyond used to do this, and Target may. So that would be something to investigate: can you go shopping now and set it so that those items are in the W-S store when you arrive.
Final thought: some families work with local UPS stores to ship boxes there and pick up once you arrive. There are 2 UPS stores close to campus, one on Reynolda Road and one on Peace Have Road that might be worth checking into.
Hope that is helpful to you in planning.