Safari browser protection to block potentially unwanted apps and insecure URLS etc.

Safari already warns the upon attempting to load a fraudulent website: Change Security preferences in Safari on Mac - Apple Support.

Typically, those sites are phishing attempts or similarly fraudulent efforts to convince a user to install something malicious, for which macOS introduces additional layers of protection: Protect your Mac from malware - Apple Support.

A website itself cannot install something malicious without a user's active participation and consent. On Macs, that requires a separate step. Safari cannot automatically install apps, extensions, or other modifications.

In addition to that, Apple offers mobile device management solutions that convey nearly limitless ability to restrict what your users can do with their Macs and other Apple devices you wish to control: Mobile device management security overview - Apple Support. Given the context of your question I think that's the direction in which you will want to proceed. A third party (non-Apple) product will never be effective, for a number of reasons.