VPN for OS 10.14

VPN in not necessary for Mac OS. Third party VPN sites offer no additional security over what Mac OS already provides so really there is no reason to search for one.

However, as you inherited the Mac please search for Apples instructions on “ what to do if you sell, give away or recycle a Mac” it is critical you follow the instructions or all you will have is a huge mess and an unhappy experience with the Mac!!

I am saying third party VPNs make Macs, slow, unstable, and cause very odd behaviours and should never be installed.

However before addressing that please follow Apples instructions on what to do before selling, giving away or donating a Mac. You can foot those words and you will find Apples steps. Please follow them.

Sounds like maybe your macOS and Safari browser (which go hand in hand) are out-dated. If you can not update the macOS and Safari do to the age of the Mac, then you can get and use a third-party browser like Mozilla FireFox to access those websites. https://www.mozilla.org/en-US/firefox/mac/

Do you have admin access to your router?

Site scan easily be blocked in a router, but they can just as easily be unblocked ... if you have proper rights

Try and log in. If you can, check for blocked sites. If you can't log in, well ... you know where you stand on that issue.

Call you ISP and ask them about blocks ... straight to the horses mouth so to speak.

It’s much more likely that your parents have blocked it on the router than your ISP blocking it. Talk to them about it.

Blocked maybe because they hog the available bandwidth?