Hi Imed
I'm doing fine, and I hope you are also well!
I'll deal with RTL first because that's quite straightforward. In any editor window in Xerte you should be able to change to RTL, using an icon that usually displays in the bottom row of the Toolbar (
xerte.org.uk/wiki/doku.php?id=texteditor) I've also attached a screenshot of the icon to help you find it. I don't think you can set up the project (or the installation) so that RTL is the default for all editor windows, but colleagues with a better technical understanding than me may be advise differently.
You asked about having the menu on the right side of the screen? I'm guessing this is for pages such as Interactive List, MultiNavigator and Tabbed Navigator+, where you click on a menu item either to reveal more text, or to take you to a different page. I think the only page which will allow you to put the menu on the right and text on the left is MultiNavigator, because you can add an Optional Property (called Panel Layout) which allows you to do this. You will also want to ensure that the menu items display RTL, and to do this you will have to add a bit of code through the Source View. You'll need to add dir="rtl" within the <p> tag for the relevant. For example, <p dir="rtl">author</p> will ensure that the word "author" is right-justified as a menu item. Again, colleagues with a better technical understanding may have more to offer you on this.
I hope this is useful. When I have time, I will try to collate some more information on authoring in languages other than English, and make it available to the Xerte community.
Best wishes
Jonathan