Added all the needed scenes and made Scene1 Play button functional

Jump Game/Assets/Scripts/Menu/ChangeScene.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+public class ChangeScene : MonoBehaviour
+{
+    // Start is called before the first frame update
+    void Start()
+    {
+        StartCoroutine(ChangeSceneToGame());
+    }
+
+    private IEnumerator ChangeSceneToGame()
+    {
+        yield return new WaitForSeconds(5);
+        SceneManager.LoadScene(3);
+    }
+}

Jump Game/Assets/Scripts/Menu/ChangeScene.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 6c194945d6efbb74b9c82c5aebdee38e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Jump Game/Assets/Scripts/Menu/Menu_Buttons.cs

@@ -1,6 +1,8 @@
-using System.Collections;
+using System;
+using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.SceneManagement;
 
 public class Menu_Buttons : MonoBehaviour
 {
@@ -59,4 +61,10 @@ public class Menu_Buttons : MonoBehaviour
         OptionVideoPanel.SetActive(false);
         OptionControlsPanel.SetActive(true);
     }
+    public void StartGame()
+    {
+        SceneManager.LoadScene(2);
+    }
+
+   
 }