Basics

In order to create a C++ file, you need a few things.

First, put all your #include statements at the top, outside of any classes or functions:

#include <iostream>
#include <string>
#include "pikachu.h"
 
using namespace std

Second, put your class headers (if in the same file):

class Player {
private:
    /* some variables */
public:
    /* some functions */
};

Third, put your function definitions:

int main(){
    /* some code */
}

Data sizes of variables:

Type	Size
bool	1 byte
char	1 byte
short	2 bytes
int	4 bytes
float	4 bytes
long long	8 bytes
double	8 bytes