I tried real mode up to a point at which NASM said "File too big" in assembly debug style language. (Error with times 256-($$-$) because there is 218 bytes of extra info

I need help from the basics such as input, interrupts, PRINTING, etc.
Oh one more thing, I'm just 13.

So please make it easily understandable.
With many a thanks,
TheCoder101
I Pray you help me.

EDIT:-
I want to use a CD to boot, with the eltorito of grub as the boot loader.
I also use linux, if that can make things better and easier for me and you
