What resolution should I choose?

I want to create a game with pixel-art graphics. The game will be consist of the one room and I want to paint this room, but I don’t know, what resolution should I choose for it. On my computer display’s resolution is 1366x768. But would it displays correct on the other computers with another resolution?

1.) Create a Guitexture set Scale at 1, 1, 1
2.) Drop this script into that Guitexture and set value as 1, 1;
3.) Set 0 at Pixel Inset under Guitexture Component.

using UnityEngine;
using System.Collections;

public class GUIAspectRatioScale : MonoBehaviour 
{
	public Vector2 scaleOnRatio1 = new Vector2(0.1f, 0.1f);
	private Transform myTrans;
	private float widthHeightRatio;
	
	void Start () 
	{
		myTrans = transform;
		SetScale();
	}
	void SetScale()
	{
		widthHeightRatio = (float)Screen.width/Screen.height;
		
		myTrans.localScale = new Vector3 (scaleOnRatio1.x, widthHeightRatio * scaleOnRatio1.y, 1);
	}
}

This script will help to fix your background resolution problem, there are more matrix solution in Here or you can use this code snippet under you OnGUI()

void OnGUI()
	{
		Vector3 scale;
		
		float ResolutionX 	= 1920;
		float ResolutionY 	= 1080;
		
		scale.x 			= (float)Screen.width/ResolutionX;
		scale.y 			= (float)Screen.height/ResolutionY;
		scale.z 			= 1;
		
		Matrix4x4 svMat 	= GUI.matrix;
		GUI.matrix 			= Matrix4x4.TRS(new Vector3(0,0,0),Quaternion.identity,scale);
	}

This will scale your button or images.