Our top tip for getting around is the national network of air-conditioned buses- the Compagnie de Transport Marocain, knows universally by the acronym ‘CTM’ - is inexpensive and reliable.
CTM journeys can be booked online - even down to specifying your prefered seat through the official CTM website. At the moment this online booking facility is only in French but it is easy enough for non French speakers to make sense of with translate. If you can’t book the ticket bus travel is probably not for you!
The main alternative bus network is Supratours a network run by the ONCF the national railway company. The Supratours route map and timetable conveniently dovetails with the railway network
The are also a great many smaller independent bus operators, some of which off.