When I bought my G17 all I did was field strip it to be sure it was clean and it was. No wipe down needed and loaded the mags and started shooting.
I have only had one gun that I have ever purchased that had the packing grease in it. All others were clean and lubed.
The manual will have directions on how to field strip the pistol or you can watch this video
This is a Glock 23 I think he said but the take down is exactly the same.
Have fun with your new gun.
After reading some of the follow up posts here I am beginning to wonder if my FFL cleans/wipes the shipping grease off all his guns.
The one gun that I had to clean I purchased from a different FFL, But my regular FFL I have never had to wipe or clean because they were already that way when I got them home.
All the guns are already in the display case so that may be what he is doing. No greasy goobered up pistols on display and all.