I'm making a game in which the rigidbody moves after he has thrown an object, and the object hits a trigger. When I put apply for after OnTriggerEnter2D the player isn't moving.

This is a 2D game. The player has to move back after he has thrown an object and this object hits the trigger. The Script is applied to objects with triggers. This is what I have:

using UnityEngine;
using System.Collections;

public class Move : MonoBehaviour {
public Rigidbody2D man;

void OnTriggerEnter2D (Collider2D other) {
	FixedUpdate ();
}

void FixedUpdate () {
	man.AddForce (Vector3.left);
}

}

How can I make my character move?

Try

man.AddForce(Vector3.left * 10)

Since Vector3.left basically is something like (1,0,0), so only 1 you might not see anything happen. Replace 10 for a variable and try increasing it for the desired effect.

The physics engine only works realistically when you obey the rules of the system. When you add force to something it is going to move a certain distance in a certain time. So when you import a object that is 10.000 units high in the engine (10KM) and zoom the camera all the way out you will no see it move if it only move 1m per second since 1 pixel could take up many kilometers. Try to keep everything on a real life scale and mass as a starting point.