To use OneDrive, you need to install the OneDrive.app from Microsoft, and log in with your Microsoft account. This will usually create a folder at /Users/username/OneDrive which holds all the files.
You can save your Papyrus files directly into this folder to have them synchronised among your devices. You can also tell Papyrus that this is a storage place somewhere on the internet using the Cloud Path setting at Settings > Document > Cloud. If you also set a password there, all files in the Cloud Path will be automatically encrypted. If you want to open them on other devices, Papyrus will ask for the password. You can set up the same Papyrus password on your other devices to open them just like normal documents.
The Mac version of Papyrus also accepts PDF as a graphics format that you can use in documents. However, if you open these .pap documents on Windows, PDF graphics will be displayed as a grey placeholder only, complaining about unknown graphics format. You can work on these files on Windows and save them just fine. When you open them later on the Mac, the PDF will be shown as graphics just like any other picture.
The print dialog is a bit weird in comparison to other Mac applications. If you want to change the printer, you have to do this in two places. First in the print dialog, then select »Options« which will open a standard macOS printer options dialog where you need to change the printer again.
The rest is basically the same.
That’s a matter of getting used to it but you can change the scroll direction in System Preferences > Mouse > Scroll Direction. Also make sure to activate Secondary Click for the right mouse button for opening context menus. Otherwise you need to use Control- Click.