Basically, you need to
1. Enable the Arabic driver, and you've got that done!
2. Set up a method for switching between layouts. That's covered by the sites I've linked to below, but you could try right-clicking on the panel and seeing if there's a keyboard indicator available. I'm sorry to be vague, but I don't know whether you have Gnome or KDE, and it's years since I've used either.
https://help.gnome.org/users/gnome-h...ayouts.html.en
https://docs.kde.org/trunk5/en/kde-w...d/layouts.html
3. Configure LibreOffice. Click on Tools - Options - Language settings - Languages. Then tick the box "Complex text layout" and select the language from the pull-down list.
There are very useful free instruction books for this software
https://documentation.libreoffice.or...documentation/
Extra
If ever you want a different Arabic font, here's a guide
http://www.wazu.jp/gallery/Fonts_Arabic.html
