how do i get my safari browser back

Hi Loan, how to set it?

https://support.apple.com/guide/safari/change-your-homepage-ibrw1020/mac

Or are you infected witgh Malware/Adware?

EtreCheck is a simple little app to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac.

http://www.etresoft.com/etrecheck

Pastebin is a good place to paste the whole report...

https://pastebin.com/

Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck.

There is also Malwarebytes which may take care of it...

https://www.malwarebytes.com/mac/