Apps and Desktops Anywhere will connect to your OneDrive account so you can access your OneDrive files from the Open and Save dialogs of hosted apps. See: Using OneDrive in Apps and Desktops Anywhere. Your legacy H:\ drive is no longer connected in Apps and Desktops Anywhere.
Using folder redirection, you can also access files stored on your iPad from hosted apps.
Windows App automatically shares your Documents folder into the remote apps. The design of Open and Save dialogs can vary depending on the developer, but your redirected folders will typically appear in the This PC view in "Redirected drives and folders".
Your Documents folder will appear as "Documents on [your iPad's name]".
To manage the contents of your Documents folder, use the Files app on your device.
To access your files, including OneDrive, see: Accessing your files in Apps and Desktops Anywhere.
To print, see: How to print in Apps and Desktops Anywhere.
For keyboard shortcuts, mouse and touch options, see: Use keyboard, mouse, touch, and pen in Windows App (Microsoft).
Microsoft Windows App automatically refreshes periodically. However, you can drag the app list down to manually initiate a refresh.
View your apps as a list or as tiles by using the View settings at the top of the list.
Tap and hold an app to add it to your Favorites.
Tap the Favorites section in the toolbar to see only your Favorites.
Tap the Windows App logo to access zoom, onscreen keyboard and other options. You can move this logo to anywhere along the edge of the screen.
Switch between apps, change resolution or switch between mouse mode and touch mode.
For additional info about using Microsoft Windows App, see Microsoft's Getting Started with Windows App guide.
If you need help, see the Frequently Asked Questions page on the Apps and Desktops Anywhere site or the Troubleshooting knowledgebase article.