help mac wont turn on

This is my first time ever installing Open Core and i tried to install it on my mid 2011 iMac, i tried to go for Ventura and with an USB of 16GB (at least thats what it said because it wouldnt stop saying once installing that it was 15GB).

It gave that mistake that shows on the photo and when i turned it off after a few hours trying it just shows the screen like its about to turn on, and when it reaches the end it just restarts again, this can go for hours, and my keyboard is bluetooth, so now idk what to do 🫠.