#include<iostream> // this will allow me to display an output and allow the player to give input into my game
#include<string>
#include<sstream>
using namespace std;

char slot[6][7]; // this will let my game store what is inside each slot of the board 
                // the board is a 7 x 6 so this creates 6 horizontal arrays with 7 slots in each (0-6)

void playerName(string& p1Name, string& p2Name)
{
    cout << "What is your name Player 1: "; // asks the players there names and stores it in a variable
    cin >> p1Name;

    cout << "What is your name Player 2: ";
    cin >> p2Name;
}

void playerInput(int& player, string& p1Name, string& p2Name, int& input)
{

        if (player == 1)
        {
        cout << p1Name << " What is your move: ";
        cin >> input; // asks and recieves the players move 
        }

        else if (player == 2)
        {
            cout << p2Name << " What is your move: ";
            cin >> input;
        }

        if (input < 0 || input > 7)
        {
            cout << "Invalid move" << endl;
            playerInput(player, p1Name, p2Name, input); // stops the player from inputting a number that doesn't coresspond to the board
        }
}

void dropCounter(int& input, int& player, int& itterations, string& p1Name, string& p2Name)
{
    bool found = false;
    itterations = 5;
    do
    {

        if (slot[itterations][input - 1] == ' ') // checks to see which is the first free space in the column that the counter can go in
        {
            if (itterations >= 0)
            {
                found = true;
            }
            else
            {
                cout << "Column Full Try Somewhere else" << endl;
                itterations = 5;
                playerInput(player, p1Name, p2Name, input); // stops player from overfilling a column
            }
        }
        else
        {
            itterations -= 1;//move up 1
        }
    } while (found == false);
}

void updateGrid(int& player, int& input, int& itterations, char& p1Symbol, char& p2Symbol)
{
    if (player == 1)
    {
        slot[itterations][input-1] = p1Symbol;
    }
    else if (player == 2)
    {
        slot[itterations][input-1] = p2Symbol; // places the counter of the respective players turn
    }
}

void display(int& player, int& input, int& itterations)
{
    for (int a = 0; a <= 5; a++) // this creates 6 rows of the shape created below 
    {
        for (int b = 0; b <= 6; b++) {
            cout << "|" << slot[a][b]; //creates board using | and places array inside the gap
        }
        cout << "|" << endl; // ending line and closes the board
    }

    cout << " 1 2 3 4 5 6 7" << endl; // this puts the numbers 1-7 under the columns 
}

void updateDisplay(int& player, int& input, int& itterations, char& p1Symbol, char& p2Symbol)
{
    for (int a = 0; a <= 5; a++) // this creates 6 rows of the shape created below 
    {
        for (int b = 0; b <= 6; b++) {
            cout << "|" << slot[a][b]; //creates board using | and places array inside the gap
        }
        cout << "|" << endl; // ending line and closes the board
    }

    updateGrid(player, input, itterations, p1Symbol, p2Symbol);

    cout << " 1 2 3 4 5 6 7" << endl; // this puts the numbers 1-7 under the columns 
}

 bool checkForWinHoz(char& p1Symbol, char& p2Symbol, int& player)
 {

     for (int a = 0; a < 6; a++)
     {
         for (int b = 0; b < 4; b++)
         {

         }
    }
}



int main()
{
    bool winner = false;
    char p1Symbol = 'x';
    char p2Symbol = 'o';
    int player = 1;
    string p1Name = " ";
    string p2Name = " ";
    int itterations = 5;
    int input = 0 ; // will use this to select an input 



    for (int a = 0; a <= 5; a++)  //for each row
    {
        for (int b = 0; b <= 6; b++) //for each column
            slot[a][b] = ' '; // assign array
    }

    playerName(p1Name, p2Name);

    do
    {
        display(player, input, itterations);
        bool verticalCheck(int slot[6][7], int player);

        playerInput(player, p1Name, p2Name, input);
        dropCounter(input, player, itterations, p1Name, p2Name);
        updateDisplay(player, input, itterations, p1Symbol, p2Symbol);
        winner = checkForWinHoz(p1Symbol,p2Symbol,player);
        if (winner == true)
        {
            if (player = 1)
            {
                cout << "Congratulations " << p1Name << endl;
                system("pause");
                //std::exit(EXIT_FAILURE);

            }
        }

        if (player == 1 && player != 3)
        {
            player = 2;
        }

        else if (player == 2 && player != 3)
        {
            player = 1;
        }
        system("cls");// erases the old table
    } while (player != 3);

    system("pause"); //keeps screen up

}

I should probably post some info.

Here is my code for Connect 4 and it works fine (if you edit out anything to do with checking for a win). I have been scouring the web for a tut i can implement into my win condition but i just can't wrap my head around checking if player 1 or player 2 has won

Any help would be appreciated

This is just bogus!

if (player == 1 && player != 3)
{
    player = 2;
}
else if (player == 2 && player != 3)
{
    player = 1;
}

Just use

if (player == 1)
{
    player = 2;
}
else if (player == 2)
{
    player = 1;
}

There are better/shorter ways to do this, but let's keep it simple. Your tests for player != 3 are irrelevant.

This is not addressing the rest of the errors in your code, but obviously you need to seriously rethink your approach.