Make sure you started a new Blank Project and not a new Console Project. From there you have to right click on the Source Files folder in your solution and add a new cpp file, eg Main.cpp
If you use Microsoft Visual Studio 20## , you must include iostream with " .h "
like this
#include <iostream.h>
some compilers can accept <iostream>
and one thing , if you want to compile your codes faster, when you want to use the Syntax "using namespace std(any classes) ;" just at the end of work see again your code and everything that your code need like "cin , cout , endl " 1 on 1 , type
using namespace class-name ; --> using class-name::object-name ;
using std::cin ;
using std::cout ;
using std::endl ;
in the Data Structure (and if you're a computer sciences student), Complexity of Time is so important for your code!