Most of Tobago has the American 110 volt system and uses the standard US two-pin plug. I'd check that anything you take, (like hair-dryer, etc), is dual voltage, and will work on 110 volts.
Accommodation with a cooker, or an electric hot water tank, usually has a 230 volt supply for these. To use this, you'd need an American 230 volt three-pin plug fitted to your appliance.