I just started using Unity 3d (5) and I noticed that my camera gizmo is different that in the tutorials I’m seeing on Youtube. I can only move left, right, up and down. This is what I have. How do I change it? 
You can look around by holding your right mouse button in the scene view. The axis gizmo is there to easily lock the camera view on a specific axis
but how to get it in isometric view ?
To get into isometric view you can click the square in the middle or click on the text below the fixture( that text that shows Front on your screenshot).
The same way you get back to perspective view if you need to.