Let me help you with this.
Please note that Secure boot, if enabled, BIOS will boot to trusted Operating System images. The Internal UEFI Shell is a command console similar to a DOS environment.
Now if you would like to boot to the AHCI driver you need to have the UEFI shell disabled and if the Operating System was installed on AHCI mode then just make sure it is set as AHCI before booting up. In regards the Secure boot, you can also keep that one disabled and you should be able to boot up without any problem.