While you can minimise the Search/Guides window, it cannot be completely hidden or fully suppressed. There are no settings to control or modify this behavioir.
To minimise the Search/Guides window, using the handle at the top edge of the window, swipe downwards to the bottom edge of the screen. The Search/Guides window should remain minimised while the Maps App is open.
If you’d like to see this functionality change, Apple invite submission of comments and feature requests via is Product Feedback portal. For iPad and iPadOS:
Feedback - iPad - Apple