What's "it" referring to here?
Native speaker’s answer
Rebecca
We have to look at the expression as a whole, which is "doing it first." "It" here likely refers to a trend, activity, or action. Thus, "to do it first" means to be the first to do something, which becomes more popular over time. Ex: Everyone is on Facebook now, but back then, the college kids did it first. Ex: A lot of stores are making bucket hats now, but Gucci did it first.