Failure to create the file firmware-util.sh Read-only file
since you haven’t bothered to tell us what you actually did to get that error, we’re left to guess (or ignore the post completely for being low-effort slop).
I’m going to guess you’re not following instructions, and either logged in as or are running the script download command as root, which means you’re trying to download to /, which will fail because it is read-only.
If you’re messing up something this basic this early in the process, it does not bode well for your prospects in being able to run another OS successfully.