Does Google Inform You If You Access a Blocked Site? Here's What You Need to Know

I don’t think Google sends notifications for blocked sites. They just block it and show an error page.

If it’s malware, you’ll see a red warning. If it’s restricted, it’ll just say the site is unavailable.

You can try using a site like Down For Everyone Or Just Me to check if the site is actually down or just blocked for you.