The normal way to do this is with Named Views.
In Modelspace you create a view and name it. Two ways to go about this, use Create View and drag a fence around the area you want to be in the View, then Name it. The other way, if you like what you see on the screen, right-click on a Standard View icon to bring up the Named View dialog and give it a name. Both do the same thing, just a little differently.
Now go into Paperspace and use "Insert / Viewport". You will insert your viewport just like you would create a rectangle. You'll get the Named View dialog; select a view, Go To, Close. Now select the VP
and go to its Properties. On the Viewport page in the Scale section, check "Fixed", then pick a scale from the list. You can overwrite what is in the list window with your own scale parameter, TC will convert it if it's not the same system currently being used.
You can insert another VP into that Paperspace and use a different view with a different scale or even the same view with a different scale.
Hope this helps
Designer, Deluxe, (Professional, Expert, Basic), Platinum
Windows 10 Pro (1803), 64-bit