how do i access my pcs bios?

i was trying to enable secure boot on my pc but accidentally did the tutorial wrong. https://www.youtube.com/watch?v=KF2vdUnzLlg i watched until 43 seconds where you have to enroll all factory default keys or around somewhere similar and reset the pc midway and now i cant access the bios at all through the load up screen or through windows as it just gives a black screen. is there a solution or do i need to see a pc repair place?