Like everyone has been telling you:
Code:
int GameStart();

int main()
{
	int strikes=0; // to tell the plyers how many wrong guesses
	int wordlength; //to tell plyers how long the word is
	char guess; //what the players will be defining to play the game
	string gameword; //the designated word from the leader
	string decision; //string for type of guessing
	string answer; //reference to the answer for the player's guess
	string lost; //choice by player to play again
	int menuchoice; //what type of meanu they want
	string success; //to decide if guessed letter is present
	string name; //Players Name
	string players; //If theres more players
	int p; //number of players
	int lives=10; //number of lives player has
	char astring[30]="-";

	system("cls");
	cout<<"Choose A Number.\n"; //Displays Menu Text
	cout<<"1. Play Game\n";
	cout<<"2. Help and Guide\n";
	cout<<"3. Exit\n";
	cout<<"Choice:";
	cin>>menuchoice;
	switch ( menuchoice ) //Allows For Menu Option Selection
	{
	case 1:
		GameStart();
		break;
	case 2:
		HelpAndGuide();
		break;
	case 3:
		exit(0);
		break;
	default:
		GameStart();
		break;
	}
}

int GameStart()
{
You can't go on like this, you know... If you haven't learned functions, it's obvious you lack a lot of basics. You need a book. Do not proceed until you know the basics. It will confuse and you will get nowhere.
C++ is not for beginners.