Man your hotel is out in the boonies across the street from Gaasperpark but not to worry it's very near to the last stop on the #53 metro (subway) line that will take you to Nieuwmarkt the stop just before Centraal Station. From Nieuwmarkt metro station it's no more than three blocks to the main RLD.
After midnight the 357 Gasperplas nightbus from Centraal Station and Damrak (Dam Square) will take you home. Probably take about 30 minutes to get there though.
Since you're way out and it's a 3 strippen ride I'd say a 24, 48, or 72 hour transportation pass is your best bet especially if you're using the night bus where only hour passes and EUR 3 are accepted.
www.gvb.nl and
www.9292ov.nl ...have all the details.