"a wolf that feeds on moose and elk would be classified within which trophic level? "

The wolf would be classified as a secondary consumer. Within the trophic levels, the base level that converts inorganic carbon to organic carbon, typically through photosynthesis, is known as the primary producer. Primary consumers would be animals that feed directly on the primary producers, and are herbivores. The elk and deer would be primary consumers in this case. Secondary consumers are predators that feed directly on primary consumers. They therefore have a meat-based diet, i.e., they are carnivores. The distinction is often not as simple as this in real life. Herbivores have been known to east a small amount of carrion to supplement their diet for example, and many predators are omnivores with a mixed plant-based and meat-based diet.