How to show different pages to different UserID’s with MVC?

I’m trying to make a Restaurant WebSite and I wanted to make Admin and Customer. Admin can create new foods that can be seen on the website or delete etc. Customer can only buy foods.

So I made a test database and it looks like this:

and made SignIn, SignUp and Logout pages and here is the codes:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using tst_MVC1.Models;
using System.Web.Security;

namespace tst_MVC1.Controllers
{
    [AllowAnonymous]
    public class SecurityController : Controller
    {
        DenemeSQLEntities db = new DenemeSQLEntities();

        public ActionResult Login()
        {

            return View();
        }

        [HttpPost]
        public ActionResult Login(tstTable user)
        {
            var userInDb = db.tstTable.FirstOrDefault(x => x.userName == user.userName && x.password == user.password);

            if (userInDb != null)
            {
                FormsAuthentication.SetAuthCookie(user.userName, false);
                return RedirectToAction("Index", "Home");

            }
            else
            {
                ViewBag.Mesaj = "Geçersiz Kullanıcı Adı veya Şifre";
                return View();
            }


        }
        public ActionResult SignUp()
        {
            return View();
        }

        public ActionResult Logout()
        {
            FormsAuthentication.SignOut();
            return RedirectToAction("Login");
        }
        [HttpPost]
        public ActionResult SignUp(FormCollection form)
        {
            DenemeSQLEntities db = new DenemeSQLEntities();
            tstTable model = new tstTable();
            model.userName = form["userName"].Trim();
            model.password = form["password"].Trim();
            db.tstTable.Add(model);
            db.SaveChanges();
            return RedirectToAction("Login");



        }

    }
}

and I want to do when someone trying to login, Controller needs to check it’s Rank and if its 1 it should show admin pages to it but its Rank below 1 it should show the Customer pages.

I thought i can get the Rank from the database and check like this but i cant get the Rank from the database:

if (userInDb != null)
            {
                if (rank == 1)
                {
                        FormsAuthentication.SetAuthCookie(user.userName, false);
                        return RedirectToAction("Index", "Home"); //its for test i wont send it to index page

                }
                else
                {
                        FormsAuthentication.SetAuthCookie(user.userName, false);
                        return RedirectToAction("About", "Home"); //"About" is for test.
                }


            }
            else
            {
                ViewBag.Mesaj = "Geçersiz Kullanıcı Adı veya Şifre";
                return View();
            }