The School of Evocation wizard's Potent Cantrip feature (PHB, p. 117) says:
Starting at 6th level, when a creature succeeds on a saving throw against your cantrip, the creature takes half the cantrip's damage (if any) but suffers no additional effect from the cantrip.
As I read it, the feature only affects evocation cantrips that require a saving throw. There are none of these in the basic rule book. Is this a typo?
The Feature does not only apply to Evocation Spells
The feature you are talking about says the following:
There is no mention of Evocation spells in the write-up. If it only worked on those, it would say so.
For comparison, see the Level 10 Evoker Feature
Note how this feature specifically says it only works on Evocation Spells. And, again, with the Second-level Evoker Feature
Source for all quotes
Potent Cantrip says that it works on "damaging cantrips." If it only worked on Evocation Cantrips, it would instead say something like "Evocation cantrips that deal damage."
Therefore, the following Cantrips from the Core Rulebook are valid under Potent Cantrip:
Once you extend out to the rest of the Rulebooks, you also add the following to the list.
An additional note to add is that the feature does not say it only applies to wizard cantrips that you cast. So if you gain access to Sacred Flame or Word of Radiance through Multiclassing or Feats, Potent Cantrip would apply to those as well.