Measurements vary from country to country Many places not only use metric but weigh the ingredients rather than measuring by volume. The good news is that many recipes are forgiving enough that the difference won’t matter, or can be corrected by adding a little flour or liquid until it feels right (a phrase I normally despise, but there we are).
You can find conversion sites online, and there are also apps for tablets and, probably, phones. The trick is figuring out whether that “cup” the recipe calls for is US or metric, that tablespoon US or imperial. If the recipe calls for you to weigh things you’re used to measuring, like flour or sugar, it’s probably European of some kind (get a good-quality kitchen scale that does grams as well as ounces if you’re going to try many of these). The publisher’s location is also a good guide, if you can determine that, but watch out for books that are written in the UK (or Australia) and published in the US without editing.
By the way, what Americans call “corn starch” the English call “corn flour.” I’ll be posting a sort of mini-glossary later this winter, but thought you might want to know about that detail now, if you’re playing with international recipes.