There is no way someone who is not trained extensively should be able to use either a dagger or a crossbow effectively in combat.
Club yes. Quarterstaff - it depends on exactly what you mean by that. Oriental Bo stick - no, 16th century English Quarterstaff - no, Galdalfs walking stick - sure.
If we want to bring logic into this discussion, you can break simple weapons into three groups:
Easy to use without training: Club, Greatclub, Small hammer, Sickle, Shortbow, Spear, Dart, Hand Axe (when not throwing it)
Hard to use in combat without extensive training: Light Crossbow, Javelin, Dagger, Hand axe (when throwing), Sling
Weapons which it is not clear exactly what they refer to and could be hard or easy depending: Mace, Quarterstaff