dloro, welcome to the forum.
I hope you have a great time on your vacation to Trinidad (and hopefully Tobago as well is on your agenda).
During the week, there are various pickup games in the Queens Park Savannah where you can pretty much go and get a game. You should get there for about 5pm and I'm sure for the most part everyone there will be accomodating when they hear your American accent. If you can come with a friend better yet so as not to throw off the numbers in the teams. The savannah is very big, but I would suggest you start your search from the area opposite the top of Marli Street, or opposite TGI Fridays.
Also you can find some games in King George V park which is opposite the Queens Park Oval.
If you are in the eastern part of the island, you can also find some good game at UWI grounds, or Eddie Hart Savannah and the same goes for the weekends. Eddie Hart has lights, so the games start there and go on late into the night as well.
PM me your details letting me know where you will be based, and I can try to link you with a couple people who play beforehand so that you don't have to go in blind.
ps: In trinidad, as is the case everywhere else in the real world outside of America, we call it Football not Soccer..