#2 Добавил AccountController.cs и представления входа и регистрации Login.cshtml, Register.cshtml.

CafeCritic/Controllers/AccountController.cs

+using CafeCritic.Models;
+using CafeCritic.ViewModels;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.AspNetCore.Mvc;
+
+namespace CafeCritic.Controllers;
+
+public class AccountController : Controller
+{
+    private readonly UserManager<User> _userManager;
+    private readonly SignInManager<User> _signInManager;
+
+    public AccountController(UserManager<User> userManager, SignInManager<User> signInManager)
+    {
+        _userManager = userManager;
+        _signInManager = signInManager;
+    }
+
+    // GET
+    [HttpGet]
+    public IActionResult Register()
+    {
+        return View();
+    }
+
+    [HttpPost]
+    public async Task<IActionResult> Register(RegisterViewModel model)
+    {
+        if (ModelState.IsValid)
+        {
+            var user = new User
+            {
+                Email = model.Email
+            };
+            var result = await _userManager.CreateAsync(user, model.Password);
+            if (result.Succeeded)
+            {
+                await _signInManager.SignInAsync(user, false);
+                return RedirectToAction("Index", "Home");
+            }
+
+            foreach (var error in result.Errors)
+            {
+                ModelState.AddModelError(string.Empty, error.Description);
+            }
+        }
+
+        return View("Register", model);
+    }
+
+    [HttpGet]
+    public IActionResult Login(string returnUrl = null)
+    {
+        return View(new LoginViewModel { ReturnUrl = returnUrl });
+    }
+
+    [HttpPost]
+    public async Task<IActionResult> Login(LoginViewModel model)
+    {
+        if (ModelState.IsValid)
+        {
+            var userName = model.Email;
+            if (userName != null && userName.IndexOf('@') > -1)
+            {
+                User user = await _userManager.FindByEmailAsync(model.Email);
+                if (user == null)
+                {
+                    ModelState.AddModelError(string.Empty, "Войти не удалось");
+                    return View(model);
+                }
+
+                userName = user.UserName;
+            }
+
+            var result = await _signInManager.PasswordSignInAsync(
+                userName,
+                model.Password,
+                model.RememberMe,
+                false);
+            if (result.Succeeded)
+            {
+                if (!string.IsNullOrEmpty(model.ReturnUrl) && Url.IsLocalUrl(model.ReturnUrl))
+                {
+                    return Redirect(model.ReturnUrl);
+                }
+
+                return RedirectToAction("Index", "Home");
+            }
+            ModelState.AddModelError(string.Empty, "Неправильный логин и (или) пароль");
+        }
+
+        return View(model);
+    }
+    
+    [HttpPost]
+    public async Task<IActionResult> LogOut()
+    {
+        await _signInManager.SignOutAsync();
+        return RedirectToAction("Index", "Home");
+    }
+}
\ No newline at end of file

CafeCritic/Views/Account/Login.cshtml

+@model CafeCritic.ViewModels.LoginViewModel
+
+@{
+    ViewBag.Title = "Вход";
+    Layout = "_Layout";
+}
+
+<div class="row">
+    <div class="col-12">
+        <div class="card w-50">
+            <div class="card-body">
+                <form asp-action="Login" method="post" asp-antiforgery="true">
+                    <div class="validation" asp-validation-summary="All"></div>
+                    <div class="mb-3">
+                        <input asp-for="Email" class="form-control" placeholder="Введите Email">
+                        <span asp-validation-for="Email" class="text-danger"></span>
+                    </div>
+                    <div class="mb-3">
+                        <input asp-for="Password" class="form-control" placeholder="Пароль">
+                        <span asp-validation-for="Password" class="text-danger"></span>
+                    </div>
+                    <label asp-for="RememberMe" class="form-label"></label>
+                    <input asp-for="RememberMe" type="checkbox">
+                    <input asp-for="ReturnUrl" type="hidden"><br/>
+                    <button class="btn btn-primary" type="submit">Вход</button>
+                    <p class="card-body">
+                        <a asp-action="Register">Регистрация!</a>
+                    </p>
+                </form>
+            </div>
+        </div>
+    </div>
+</div>
+
+@section Scripts
+{
+    @{
+        await Html.RenderPartialAsync("_ValidationScriptsPartial");
+    }
+}

CafeCritic/Views/Account/Register.cshtml

+@model dynamic
+
+@{
+    ViewBag.Title = "Регистрация";
+    Layout = "_Layout";
+}
+
+<div class="row">
+    <div class="col-12">
+        <div class="card w-50">
+            <div class="card-body">
+                <form asp-action="Register" method="post" asp-antiforgery="true">
+                    <div class="validation" asp-validation-summary="All"></div>
+                    <div class="mb-3">
+                        <input asp-for="Email" class="form-control" placeholder="Email">
+                        <span asp-validation-for="Email" class="text-danger"></span>
+                    </div>
+                    <div class="mb-3">
+                        <input asp-for="Password" class="form-control" placeholder="Пароль">
+                        <span asp-validation-for="Password" class="text-danger"></span>
+                    </div>
+                    <div class="mb-3">
+                        <input asp-for="ConfirmPassword" class="form-control" placeholder="Повторите пароль">
+                        <span asp-validation-for="ConfirmPassword" class="text-danger"></span>
+                    </div>
+                    <button class="btn btn-primary" type="submit">Зарегистрироваться</button>
+                    <p class="card-body">
+                        <a asp-action="Login">Войти</a>
+                    </p>
+                </form>
+            </div>
+        </div>
+    </div>
+</div>
+
+@section Scripts
+{
+    @{
+        await Html.RenderPartialAsync("_ValidationScriptsPartial");
+    }
+}