how do i get TcpListener to accept multiple connections and work with each one individually?

You can factor out most of your code into a separate thread:

static void Main(string[] args)
{
    TcpListener listener = new TcpListener(IPAddress.Any , 8000);
    TcpClient client;
    listener.Start();

    while (true) // Add your exit flag here
    {
        client = listener.AcceptTcpClient();
        ThreadPool.QueueUserWorkItem(ThreadProc, client);
    }
}
private static void ThreadProc(object obj)
{
    var client = (TcpClient)obj;
    // Do your work here
}

You almost certainly want to spin each connection into another thread. So you have the "accept" call in a loop:

while (listening)
{
    TcpClient client = listener.AcceptTcpClient();
    // Start a thread to handle this client...
    new Thread(() => HandleClient(client)).Start();
}

Obviously you'll want to adjust how you spawn threads (maybe use the thread pool, maybe TPL etc) and how you stop the listener gracefully.

I know this is old question but I am sure many will like this answer.

// 1
while (listening)
{
    TcpClient client = listener.AcceptTcpClient();
    // Start a thread to handle this client...
    new Thread(() => HandleClient(client)).Start();
}

// 2
while (listening)
{
    TcpClient client = listener.AcceptTcpClient();
    // Start a task to handle this client...
    Task.Run(() => HandleClient(client));
}

// 3
public async void StartListener() //non blocking listener
{
    listener = new TcpListener(ipAddress, port);
    listener.Start();
    while (listening)
    {
        TcpClient client = await listener.AcceptTcpClientAsync().ConfigureAwait(false);//non blocking waiting                    
        // We are already in the new task to handle this client...   
        HandleClient(client);
    }
}
//... in your code
StartListener();
//...
//use Thread.CurrentThread.ManagedThreadId to check task/thread id to make yourself sure