How should you handle things on vacation? The bottom line is to enjoy the time on trips but make choices that aren't going to set you way back.
When eating out of your normal environment, first look at portion control. Second, start with your protein, make sure you have a decent amount (size of palm is a good indicator). Next, get some sort of veggies in there. Fourth, on carbs, make sure they are in check. I would keep portions no bigger than size of fist. Finally, keep the fat in check, which usually is controlling sauces and toppings.
Stay active, if you want to get up and moving, either a jog or just do bodyweight exercises. There might be a legit gym nearby if you have time and want to search.
Again, enjoy the time, don't stress on it, be mindful of portions and have a safe, fun trip!