which is certainly not an easy tutorial to follow. Seems like more robustness tends towards a greater barrier to entry.
It's a lot easier and nicer to use either UEFI or a Multiboot-protocol bootloader (GRUB, or qemu/bochs built-in bootloader). That also means you will be starting in long mode or protected mode.
In order to work with bare metal efficiently, you need to get a debuggable and bootable ELF image up and running as soon as possible. Once you can attach a remote GDB debugger to Qemu, you get things done much faster than using the Qemu/Bochs monitor/debugger.
Anything more complex than a hello world example is easier with UEFI or multiboot than BIOS boot sectors. You will need a linker script and a build script but things will be much easier after the first steps.
I made this pull request for someone else's bare metal project to add debuggable ELF images. It's a small but practical example: