Hi there.
I registered for a Shopify account a month or two ago. I’m only now starting to set anything up. I went to look at a preview of the site to start designing when I realized there’s a bunch of code at the top of the page. I changed out the theme in hopes that would work but it didn’t. I tried looking up to see who else has asked about this, but it looks like previous posts about this has only led to people asking the users to message them or something? Any help would be appreciated. I’m clearly not a professional web designer or programmer. 
EDIT: I found some help through an old reddit thread! Apparently, if you have a SurveyJunkie app called “Surf to Earn” on your PC, it’ll cause this issue.