Congratulations. I hope you enjoy your foray into absinthe.
(after looking up your purchase) Whoa! Good luck with that stuff. Czech absinthe is generally quite strong, but can be quite tasty! Just be sure to stay away from Hills or almost any blue colored brands. You might want to check out
LFD for future purchases. They have some of the best commercial quality absinthe including Jade, probably the closest you can get to how Absinthe was really made during the height of its popularity.
blackpants: Unless your friend is a complete lightweight, one shot should be no worse than say a shot of Bacardi 151. You might feel pretty good after the one shot, but you shouldn't be "completely trashed".