1. Finder > Applications
If you find an application with a name similar to Safe Finder,
right click on it and choose “Move To Trash”.
2. Disable Extensions and test.
Safari > Preferences > Extensions
Select and disable all extensions and test.
Enable Extensions one by one and test.
To uninstall any extension, select it and click the “Uninstall” button.
3. Safari > Preferences > Search > Search engine:
Select your preferred search engine.
4. Visit the site you want it be the Home page.
Safari > Preferences > General > Homepage
Click the button “Set to Current Page” button.
5. If this does’t help:
Use Malwarebytes Anti-Malware for Mac to remove adware.
https://www.malwarebytes.org/antimalware/mac/
Download, install , open, and run it by clicking “Scan for Adware” button to remove adware.
Once done, quit Malwarebytes Anti-Malware.