So no hard copies will be pressed. The link for that should be in this thread somewhere.
For PS4 digital download, you simply navigate over to the store, find the game you want, select the PURCHASE button and click. If you have a linked Credit Card, it'll pop up a confirmation screen. If not, I believe it will ask you for the credit card number and SSC/PIN. Once payment is accepted, there should be a download button on the next screen. I think mine just automatically starts downloading, but not sure if I set that up or not. Exit out and the game tile will be on your scroll list and the green download status bar will be under it till it finishes.
Oh and one more thing, make sure you have space on your PS4 HDD. If not, you'll have to clear space. I'd highly recommend a newly supported external SSD/HDD. It's very easy to set up and move stuff.
Guide here ->
http://www.playstationlifestyle.net/2017/03/10/ps4-external-hdd-setup-guide/
Only issue with this is the fact that the PS4 has 2 USB ports on the front and this will take one of them. Looks silly IMHO but it's functional so...