C# Client (String array, Bytes, Internal Error, Arguement Error)

So what would you recommend as an alternative.

I made some changes,

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Threading;
using System.Net;

namespace DrawDumpSyringe
{
    public partial class Form1 : Form
    {
        int i;
        TcpClient client; // Creates a TCP Client
        NetworkStream stream; //Creats a NetworkStream (used for sending and receiving data)
        byte[] buffer = new byte[1024]; // creates a new byte with length 1024
        
        public Form1()
        {
            InitializeComponent();
        }

        private void btn_connect_Click(object sender, EventArgs e)
        {
            try
            {
                client = new TcpClient(); //Trys to Connect
                client.Connect(iptextBox.Text, 80); 
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message); // Error handler :D
            }

        }

        private void btn_Draw_Click(object sender, EventArgs e)
        {

            if (client.Connected) // if the client is connected
            {
                buffer[0] = 43;
                stream.Write(buffer, 0, buffer.Length);

            }
        }

        private void btn_Eject_Click(object sender, EventArgs e)
        {
            if (client.Connected) // if the client is connected
            {
                buffer[0] = 44;
                stream.Write(buffer, 0, buffer.Length);

            }

        }
    }
}

Not sure if they are correct, honestly it does not seem that they are and it resembles a Serial port too much for me.