Before I go too far trying Scene Builder

pom.xml

         <!-- dependencies -->
     </properties>
 
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/com.jfoenix/jfoenix -->
+        <dependency>
+            <groupId>com.jfoenix</groupId>
+            <artifactId>jfoenix</artifactId>
+            <version>8.0.7</version>
+        </dependency>
+
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>

src/main/java/rocks/zipcode/atm/CashMachine.java

         accountData = data;
     };
 
+    private boolean errorExists = false;
+    private String errorMessage = null;
+
     public void login(int id) {
         tryCall(
                 () -> bank.getAccountById(id),
 
     @Override
     public String toString() {
-        return accountData != null ? accountData.toString() : "Try account 1000 or 2000 and click submit.";
+        String displayString;
+        if (errorExists) {
+            displayString = errorMessage;
+        } else {
+            displayString = accountData != null ? accountData.toString() : "Try account 1000 or 2000 and click submit.";
+        }
+        return displayString;
     }
 
     public <T> void tryCall(Supplier<ActionResult<T> > action, Consumer<T> postAction) {
         try {
             ActionResult<T> result = action.get();
             if (result.isSuccess()) {
+                errorExists = false;
                 T data = result.getData();
                 postAction.accept(data);
             } else {
-                String errorMessage = result.getErrorMessage();
+                errorExists = true;
+                errorMessage = result.getErrorMessage();
                 throw new RuntimeException(errorMessage);
             }
         } catch (Exception e) {
             System.out.println("Error: " + e.getMessage());
         }
     }
-}
+}

src/main/java/rocks/zipcode/atm/CashMachineApp.java

 package rocks.zipcode.atm;
 
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.control.Label;
+import javafx.scene.layout.GridPane;
+import javafx.scene.layout.StackPane;
 import rocks.zipcode.atm.bank.Bank;
 import javafx.application.Application;
 import javafx.scene.Parent;
  * @author ZipCodeWilmington
  */
 public class CashMachineApp extends Application {
-
+    private Stage window;
+    Scene mainContent, loginScene;
     private TextField field = new TextField();
     private CashMachine cashMachine = new CashMachine(new Bank());
 
-    private Parent createContent() {
+    @Override
+    public void start(Stage stage) throws Exception {
+        window = stage;
+        window.setTitle("Zip Cloud Bank");
+
+
+        //Log In Layout
+        Label loginLabel = new Label("Welcome to Zip Cloud Bank!\nPlease log in.");
+        Button btnLogIn = new Button("Log In");
+        btnLogIn.setStyle("-fx-font-size: 15pt");
+        btnLogIn.setOnAction(e -> {
+            mainContent = new Scene(mainContent());
+            window.setScene(mainContent);
+        });
+
+        GridPane loginLayout = new GridPane();
+        loginLayout.setHgap(12);
+        loginLayout.setVgap(12);
+        loginLayout.setAlignment(Pos.CENTER);
+        loginLayout.getChildren().addAll(loginLabel, field, btnLogIn);
+
+        loginScene = new Scene(loginLayout,600, 600);
+        window.setScene(loginScene);
+
+
+        window.show();
+    }
+
+    private Parent mainContent() {
         VBox vbox = new VBox(10);
         vbox.setPrefSize(600, 600);
 
         return vbox;
     }
 
-    @Override
-    public void start(Stage stage) throws Exception {
-        stage.setScene(new Scene(createContent()));
-        stage.show();
-    }
-
     public static void main(String[] args) {
         launch(args);
     }

src/main/java/rocks/zipcode/atm/CashMachineSkin.fxml

 
 <AnchorPane xmlns="http://javafx.com/javafx"
             xmlns:fx="http://javafx.com/fxml"
-            fx:controller="$CONTROLLER_NAME$"
+            fx:controller="rocks.zipcode.atm.CashMachineApp"
             prefHeight="400.0" prefWidth="600.0">
 
 </AnchorPane>

src/main/java/rocks/zipcode/atm/bank/Bank.java

 
     public Bank() {
         accounts.put(1000, new BasicAccount(new AccountData(
-                1000, "Example 1", "example1@gmail.com", 500
+                1000, "Gulliver Grimwald", "ggrim@gmail.com", 500
+        )));
+
+        accounts.put(6666, new PremiumAccount(new AccountData(
+                6666, "B. L. Zebub", "mephis@hotmail.com", 666
         )));
 
         accounts.put(2000, new PremiumAccount(new AccountData(
-                2000, "Example 2", "example2@gmail.com", 200
+                2000, "Richard Ricardo", "rricardo@business.com", 20000
+        )));
+
+        accounts.put(0420, new BasicAccount(new AccountData(
+                0420, "Guy Dudero", "lmfao4eva@ymail.com", 69
+        )));
+
+        accounts.put(9999, new PremiumAccount(new AccountData(
+                9999, "Final Boss", "bosskey@gmail.com", 9999
+        )));
+
+        accounts.put(0001, new BasicAccount(new AccountData(
+                0001, "Bill Busker", "bboy@yandex.com", 0
         )));
     }
 
 
     public ActionResult<AccountData> withdraw(AccountData accountData, int amount) {
         Account account = accounts.get(accountData.getId());
-        boolean ok = account.withdraw(amount);
+        boolean canWithdraw = account.withdraw(amount);
 
-        if (ok) {
+        if (canWithdraw) {
             return ActionResult.success(account.getAccountData());
         } else {
             return ActionResult.fail("Withdraw failed: " + amount + ". Account has: " + account.getBalance());