New milk snake not eating

[Masharms13]

Hello everyone, I’m new to the forum and a snake newbie. I just purchased an albino Nelson’s milk snake that’s very young. He’s in a 20 gallon long setup with a heat mat on one end on a thermostat set to 86, two hides one on each side and aspen substrate. I got him three days ago and was told by the pet shop owner I could try and feed him last night. I wasn’t sure because most of what I’ve read said to wait 5-7 days to feed a new snake but I tried anyways with tongs and he just bolted. This was right before I went to bed so I left the rodent in the cage for a few hours then got up and removed it as it was uneaten. Is this normal? When should I try to feed again and how?