Hi,
I'm Ahmed and I am here & happy to help.
Yes, it's safe because Secure Boot prevents malware, rootkits, and other threats from running during the startup process, reducing the time and power consumption of the startup process, and enhancing the stability and compatibility of your system.
1- You need to first check your system mode (legacy BIOS mode or UEFI mode) to enable Secure boot. To check the status of Secure Boot on your PC:
Go to Start.
In the search bar, type msinfo32 and press enter.
System Information opens. Select System Summary.
On the right-side of the screen, look at BIOS Mode and Secure Boot State. If Bios Mode shows UEFI, and Secure Boot State shows Off, then Secure Boot is disabled.
You can turn on Secure Boot only with UEFI mode.
Source: https://learn.microsoft.com/mem/intune/user-hel...
I hope this helps! Let me know if you have any further questions or concerns.
Best regards,