Where in the common app would we list we’re first generation if we are?
On the common app, under the family section, you indicate the level of education of parent 1 and/or parent 2 (it is a drop down menu). Admission officers will determine whether you are 1st gen based on the answer to these questions.
Put another way, there is no box to check on an app that asks, “Are you first generation?” You simply list your parent(s)’ education, and each college will use that info as it sees fit (if at all).