On a trad climbing course you should expect to learn about things as diverse as:- legal access to the crags; use of a guidebook to choose and locate climbs; basic safety and 'crag etiquette'; ropes and equipment; climbing technique and skills; belaying skills; using traditional climbing protection; choosing anchors; building belays to safeguard yourself and your partner; and probably abseiling too.
All of these are essential topics to climb legally, responsibly and above all safely.