Footer length

Hi,

This is the first time I’m creating a website so have no real idea of what I’m doing. Found this plugin very helpful in the beginning but for some reason the footer only covers the left corner of my emails when I view them on a computer (they cover the entire length of the page when viewing them on my phone though), is there a way to change this?

The emails also seem to be too big for the screen on my computer and I can scroll sideways, can I change that?

Thank you!