User Limits on Delivery App

Hi Everyone!

I had just finished a web app for small business food delivery, but i would like to know what the limits of my app are, how many users can use at the same time, how many customers the food company can have on a day.

How can I know this? Besides the limits of Firebase, Airtable and so on, it will only depends on the client’s wifi internet?

I have login through firebase, some APIs like mapquest.