Loves Falls is the easy hiking choice near Sierra City. From the Highway 49 crossing of the Pacific Crest Trail, it is a short walk to the North Yuba River and a small falls tucked into the forest.
The walk is useful even if you are not a long-distance hiker: it gives a quick feel for the PCT corridor without committing to the big climb toward the Sierra Buttes. Wear real shoes; the trail can be dusty and uneven even on a short outing.