UnityEngine.SceneManagement does not exist

I downloaded a free version of Unity on 2019-05-10 so that I can learn Unity. I get this error:
Assets/Scripts/myscript.cs(2,19): error CS0234: The type or namespace name `SceneManagement' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?
Line 2 of the script contains: using UnityEngine.SceneManagement;

In the Unity Editor, Help.About shows Unity Version 5.0.0f4 Personal (c) 2015.
I know that Unity 5.3 exists and possibly beyond that. I tried downloading the latest version, but About still displays 5.00f4.

Giving that I am using a free version of Unity, is there any way I can update to a new version to get access to SceneManagement?

 

Unity 5 is really old, download the latest version (Unity 2019.1.3) here: https://unity3d.com/get-unity/update

Before the SceneManager came out, you would load and unload scenes using functions of the "Application" static class.

 

Free vs paid Unity is just the license you're using. You can use any version of Unity you want. I'd suggest switching to Unity 2018.4.0 LTS at this time. You can download it here:

https://unity3d.com/unity/qa/lts-releases

Unity supports the installation of multiple versions at the same time, but if you install to different directories the old shortcut will still point to the old version. You'd launch using the new shortcut from the new installation. If this is too complicated, switch to using Unity Hub to manage your versions, etc. Should be easy to find the download to that.

 

Thanks for your reply. I have four Unity icons on my desktop now. They are named UnityHub, Unity 5.00f4, Unity 2019.1.2f1, Unity 2019.1.3f1. If I click on UnityHub it shows my project, I can set the Unity Version to 2019.1.3f1. But I do not know how to open it from there. If I click on Unity 2019.1.3f1, the About displays version 5.0. If I create a new project, it still shows version 5.0. Should I delete the older two versions? I have tried adding using UnityEngine.SceneManagement in the new version, and I still get the error. Any suggestions?

 

In UnityHub, I selected Version 5.1.3 for my project, but I still get version 5.0.

 

But why are you trying to learn Unity on these old versions?

 

I thought I was downloading the latest version. Today I downloaded versions 5.1.2 and 5.1.3. I do not know why I got two different versions. I deleted the shortcuts for 5.0 and 5.1.2. When I click on 5.1.3 it displays version 5.0. In Programs under Control Panel, only Unity 5.1.3 and Unity Hub are displayed, but I still see Version 5.0 when I open 5.1.3

 

I deleted Unity 3D and Unity Hub and Unity Web Player which I read was dangerous and then downloaded Unity Hub and Unity 3D 5.1.3 again. That took care of my problem. I miss MonoDevelop and do not have the Memory/Speed on my laptop to run Unity with the Visual Studio C# editor, so I resorted to J-edit for now