Hi @bonnieforsyth, it looks like this service is using it's own forms layout and styling controls: http://support.myguestlist.com.au/kb/article/256-styling-your-event
The embed that is on the blog page has no styling at all applied currently, so one option to try might be to create some styles on the site for the styles shown in the published form:
Class Names from the form embed:
MGLLabel - style for form field labels
MGLField - style for form field inputs, i.e. text input for email and name
MGLSubmit - style for form submit button
MGLPoweredBy - style for the powered by link added to the form
Create a new form so that it looks the way you want using just those class names and style the fields how you want it to look. There is not a lot of control to the structure, because the form elements are getting generated automatically from myguestlist.
After creating some new styles, delete the new form as that was used just to create the styles.
Publish the site and see if it has any affect to the styling. Alternatively, check the "Styling your Event" link I shared above.
I hope this helps!