Custom domain on Google "not secure"

Finally connected my Squarespace custom domain, www.HappinessBooster Shot.com, to my new Google blog. When I enter the url into Chrome it says "site not secure". I spent a week creating the blog and getting/connecting a custom domain and now I can't use if it's "not secure". Help.

btw, I am non technical.

Also, I could not log in to Squarespace, you hide the log in.