There should be a Terminal window that pops up if there isn't one already when you click Build and Run. If one doesn't, show it by either using Command+Shift+R or Run->Console. And to test a Hello World program doesn't take much, you can use a small C program for it.

#include <stdio.h>
int main(int argc, char** argv) {
printf("Hello World!\n");
return 0;
}