Safari searches are diverted to unwanted sites. How do I fix this on my MacBook Pro

Your Mac has been infected with malware (not as bad as a virus).

Download Malwarebytes (free version is fine) - See https://www.malwarebytes.com/ and let it run.

Whether this works depends on the malware but it's worth a try; there's nothing to lose.

Mr. Gee wrote:

Browser has been hijacked and searches are diverted to websites not wanted

Kindly download and run (free) EtreCheck, and share the report to the clipboard. Then open a new reply here, and press the Additional Text button (that looks like a printed page) to get a text input box big enough to paste the hardware and software configuration report here, and paste and post that report here.

I would not suggest any add-on anti-malware just yet. The built-in anti-malware works pretty well. These cases tend to not be malware, they tend to be deliberately-installed adware or coupon-ware or related. Which really isn’t a good fit into anybody’s definition of malware.