In the lower section of your screen menu at the very bottom you will find the Status bar. Typically, you use it to set your Ortho, Polar, and Osnap settings, etc. If you look a little further to the right there is a little Lock icon.
If you pick on this lock while you are in Paperspace viewport, it will Lock and Unlock the viewport view so you can zoom and pan around. This feature is so much faster than having to right-click the viewport border and then select Display Locked on the right-click menu.
Just to the right of the Lock icon is popdown menu that lets you select any scale factor you would like to set in the viewport. If you're a veteran of the earlier versions of AutoCAD, you will remember that you had to know and type in the zoom scale factor such as 1/48xp. That would give you a 1/4"=1'-0" scaled viewport. Is that old technique nuts, or what?!
So now you set your viewport scale and lock and unlock your viewports very quickly. Simple time saving features like this make upgrading your AutoCAD well with the money.
Have a great day! Kevin