Menu Bar > Page Size

By hovering over Page, you can select which sized paper to use for your drawing:

A Paper Sizes

• A3
• A4

B Paper Sizes

• B3
• B4

US Paper Sizes

• Letter
• Legal
• Ledger

Checkout this article to learn how to choose your Default Paper Size. 

The location of title block data needs to be setup for each individual page size once, for the system to make it a default setting when you select a page size for future use.