Arroyo Seco Weekend: A dad tackles his first music festival as a parent. Someday, they'll laugh about it.

It’s an enlightening experience, attending your first music festival as a parent after a lifetime of untethered fandom. Turns out you have to plan things.

Do not improvise Baby’s debut festival, as my wife, Jenny, and I did Saturday when we took our toddler daughter, Liza, to the first day of Arroyo...