We haven't sailed on the Westerdam yet but have sailed on the Volendam, Veendam, Maasdam and Statendam and all of these ships did not have a simulator or a place to practice putting.
You may find your answer by logging on to HAL's website and browsing around. Also, you can contact HAL through email, phone, etc. and, hopefully, they can answer your questions in a timely manner. If you're booking through a TA, that person may be able to help you as well.
Happy Cruising!