A few problems trying to boot up

i ve experienced a few problems after building my pc. I cant seem to boot into windows installation, even with the usb stick with the install program in it, and its set as the boot option 1.

My ram doesnt get the 6000mhz advertised, i tried activating xmp/expo and reboting but it failed , i got the message a message around the lines of: couldnt verify secure boot violation invalid signature detected.

Also my ssd doesnt appear under nvme configuration.