A kids desk is usually light enough for one person, especially once you pull the bolt-on legs and tape the drawers shut. The awkward part is the shape, not the weight.
Pro tip: Removing bolt-on legs takes five extra minutes but often means the difference between carrying the desk solo versus needing a second person for an awkward, leggy shape.
Watch out: Do not carry a desk by its drawers or handles, since these are rarely load-bearing and can pull loose under weight.