Some pieces that I like for students transitioning at your level, because the notes are easy and you’re free to concentrate on getting your feet going:
Dance of the Little Fishes (Dewey Owens, from Impressions on Pedal Patterns for Young Harpists)
Song at Night and Ebbing Tide by Lucien Thomson
All these were written specifically to teach pedals. For instance, Song at Night is meant to teach you the pedals on the left side of the harp, while Fishes is a study in moving the F pedal to all three positions while you play.