Hi dayna214,
Thank you for posting in the Apple Support Communities. It looks like you're having some trouble accessing some websites that you should be able to access, correct? If so, we would love to help see if we can get the issue resolved for you.
Let's go ahead and follow the steps to check your connection and make certain the recommended settings are set as they should be. You'll specifically want to check the security setting and make sure it is set to WPA3 Personal for better security, or WPA2/WPA3 Transitional for compatibility with older devices. You can visit this link we've provided for specific instructions: Recommended settings for Wi-Fi routers and access points - Apple Support
Also check the info here which also states to contact the school: If you see a "Not Secure" warning while browsing the web with Safari - Apple Support
"Never provide your password or credit card numbers to sites with this warning. If you need to use the site, contact the site owner or administrator and let them know that their site isn't secure. "
We're always happy to help. Cheers!