In this tutorial, Yagisanatode (@LifeOfSpy) is going to build a simple seat booking Google Form that will contain a registeree’s name and the session that they wish to attend. Each time a registeree submits a request to book a seat for a session, that seat is taken from the list displaying only the remaining seats for that session for when the next user submits the form.
Source: Create a seat booking form with Google Forms, Google Sheets and Google Apps Script – Yagisanatode