Hi @raquelfreit and welcome to the community!
I'm a bit confused when you say straighten the view. Do you mean like how you could click a side of the viewcube and the camera would straighten out?
The viewcube isn't supported in Viewport 2.0, however you can straighten the camera based on an object.
For example, if you have a cube, you can select one face then go to View->Align Camera to Polygon and that will align the Camera to the polygon and straighten it out accordingly.
Please let me know if this helps or if you need any more assistance!
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