That error means that your opening curly braces { and closing curly braces } are not correctly matched. You need to add or remove one of those somewhere.
If you use proper indentation in your programs (and then use code tags properly when posting them, so that the indentation is preserved), then that often gives a hint on where to look for the problem. But this isn’t 100% reliable, because there’s no guarantee your indentation isn’t also wrong. Ultimately you need to look carefully at your braces and think about where they’re supposed to go.
If you add one to the end of the class, and it generates another 10 errors…that does NOT mean that was the wrong place! Maybe your code just has 10 other errors that the computer didn’t notice before because this error prevented it from getting that far in interpreting your code. You’d need to actually look at the other errors and see if they make sense, or if they look like misunderstandings caused by the context of having curly braces in the wrong places.