You can set the tab to open by default. If you haven't used the beorg init.org before see https://beorg.app/learning/excluding-tasks-from-specific-files-for-the-agenda-and-todo-lists/. Then in your init.org add (substitute todo for files if wanted):
(set! ui-start-tab "todo")
+ Tap the Settings tab
+ Start the REPL (top right button)
+ Tap the REPL help (top right button)
+ On the first line of the help is a link to show library.org
The library.org available above does include some documentation (although could be improved) to give you an idea of what can be changed.