Code that adds row, based on user input?

Hi guys,

My title is possibly making this sound more simple than it is, as i've spent 2 days researching coding and having a go my self to no avail

I won't try to explain my self, as I feel the example attached speaks for its self.

If someone could advise exactly what I need to be looking for, or write me the code so I can mess with it, I would be eternally greatful!

Thanks
Luke