Welcome to R2R!!
Sadly, I echo the others. See if the LFS or a friend or someone from a local reefing club can hold the little guy for ya.
Mandarin really needs an established tank with a healthy population of pods to feed it since they can be picky eaters and that is their favorite food. I believe they prefer copepods to amphipods as the amphipods can sometimes be too big of a bite.
If you can't get anyone to hold it, see if you can rush an order of pods from Algae Barn to give it something to eat so it doesn't starve. <3
Mandarin Feeder Kit™ Addressing the major short- and long-term challenges in providing adequate sustenance for dragonets, the Mandarin Feeder Kit is a true blessing for pet mandarin fishes everywhere. This select package includes NanoBrine, 5280 Pods and Pod Pate.
www.algaebarn.com
Each 16oz portion of 5280 Pods contains 5280+ LIVE Tigriopus, Tisbe, and Apocyclops Copepods ranging from nauplii to adult sizes. 5280 Pods is great for seeding new tanks and refugiums, boosting existing populations, or feeding finicky fish & inverts such as Mandarins, Seahorses, Anthias...
www.algaebarn.com