I'm not sure how to word exactly what I'm looking for so, please bear with me!

I have a form, I was thinking I would put it into Excel, but I want it to
generate the next form number on it's own every time it's opened.

Almost like an invoice number, but something that I would not have to track
on paper, I just want to trust that the number that appears is the next
document.

Is this possible? Or is there a different program I should set this form up
in?

Thanks!