You can easily switch between the paper space and the model space using the tabs located at the bottom-left corner of the drawing area; there will be one tab for the model space called Model, and two (or maybe more) tabs for the paper space, called Layout1 and Layout2, as shown:

Hovering over the inactive tabs will show a small preview of the contents of this tab. This will work with either the paper space tabs or the Model tab, as shown here:

You can only have one Model tab in the drawing file; on the other hand, you can have multiple paper space tabs. You can also create new paper space tabs and delete existing ones. To create a paper space tab, click on the small plus sign on the right side of the last paper space tab and a new Layout tab will be created, as shown here:

If you right-click on any of the existing paper space tabs, you will find a number of options to manage them, as shown in the following screenshot. You can delete an existing tab or rename it; you also have the Move or Copy... option, which allows you to create an exact copy of an existing paper space tab, or just change its position. Choose the new location of the tab (or the copy) then press OK. Alternatively, to change the tab's position, you can simply click and drag the tab and move it to the desired position:

As mentioned earlier, the purpose of the paper space tabs is to prepare your model/drawings for printing. You can manage the printing paper area by adding different viewports showing different parts of your drawing/model, with each viewport having a different printing scale. In addition, you can also add a title block for your drawing, showing all the relevant information.