Hi rickertt,
Yes, you can. To play a practice round just load up the game client and click SINGLE
PLAYER GAME and then SELECT COURSE. If you select Kiawah
Island, Bethpage or St. Andrews then select STROKE PLAY from the
menu. Right below that you'll see an option for ranked or practice
rounds. If you choose practice you'll be able to setup your own
conditions and your stats will not be saved to your profile.
If you select Oakmont you'll be redirected to the USGA siteshell.
From there just choose EXPERIENCE OAKMONT and then PLAY SINGLE
PLAYER. After clicking that you'll see the options to set up a
ranked round or practice round.