Mains supply here is 120V at 60Hz, using plug types A, B.
A plug adapter changes the shape of the pins and nothing else. A single-voltage kettle from a 120V country will not work safely on a 230V supply no matter which adapter you use — check the label on the appliance for a dual-voltage range before you pack it. More on travel kettles and voltage →
What to expect in the room
Resort properties usually provide a coffee maker or capsule machine; smaller and city hotels more often rely on the lobby or restaurant. Locally grown coffee is frequently supplied and is often very good.