How do I put 2 boxes next to one another, e.g. Full Name and E-mail address

Hello jaharris.

You can do so by using Field-Positioning. I have done so on a cloned version of your form, which can be seen here:

http://form.jotformpro.com/form/51605111530944

If this is what you wanted to achieve, you can do so by Shrinking all the desired fields, and then selecting which ones would go to the new line.

Please let us know if you need further assistance, we will be happy to help.