Android - executing different functions with multiple threads

I am pretty new to Android programming but got some experience in other languages. I want to create an APP which is principle working like this.

1. The APP is a process which is asking my Web-/Database-Server every 10 seconds if there is an event to execute.

2. The Web-/Database-Server answers with an event id or even a function name.

3. The APP opens a new thread which executes the event with the id or even better directly the function name.

My Questions are:

1. Is this perfomant? Or can this chrash pretty easily?
2. Is it limited to 2 threads within the process or can I even open every time a new thread for the function which I want to execute? Maybe because of the other function is still running?

3. How can I execute a function with the return value? For example

   InputStream in = response.getEntity().getContent(); //Get the data in the entity

   public in(void) { // execute a function which got´s the same name as the variable "in" }

The result should be: The one thread is asking every 10 seconds my Web-/Database-Server if there is an event. The event gets executed within a thread and this is working parallel (at the same time without crashing or even getting stucked).

Sample Code of these Threads would be appreciated.

My code till yet:

public class service extends Service { private static final String TAG = "MyService";

@Override
public IBinder onBind(Intent intent) 
{
    return null;
}

public void onDestroy() 
{
    Toast.makeText(this, "My Service Stopped", Toast.LENGTH_LONG).show();
    Log.d(TAG, "onDestroy");
}

@Override
public int onStartCommand(Intent intent, int flags, int startid)
{

    Toast.makeText(this, "My Service Started", Toast.LENGTH_LONG).show();
    Log.d(TAG, "onStart");

    Thread thread = new Thread(new Runnable()
    {
      @Override
      public void run()
      {
         new Timer().scheduleAtFixedRate(new TimerTask() 
         {
          @Override
            public void run() 
          {
                     System.out.println("Send GO!");
                     Device dev = new Device();

                     dev.getDeviceId(getBaseContext());
                     dev.getEmail(getBaseContext());

                     dev.sendDeviceItems();
                   }
               }, 0, 10000);//put here time 1000 milliseconds=1 second
          }
          });

    thread.start();   
    return Service.START_STICKY;
   } }