It's possible there is a firewall up on your school's network that is blocking our site. Your IT specialist can confirm and help!
Let them know that we use https://www.remind.com/sign_in
If you're on a home network, its possible that the browser has certain protection settings blocking our site. It is helpful for us to know the browser you're using, that you're successfully connected to home wifi and that other sites you visit regularly are displaying properly on your computer.