Question (1): How to install Knoppix from USB PenDrive to HDD on a laptop with Win10 pre-installed?

A used laptop received with only Win10 installed. My need is to install Knoppix and Debian and later on do away with Doze.

The HDD has been suitably partitioned using gparted using Knoppix8.2 on USB PenDrive. The details are here: HP_i3_4Gen_Laptop_rajibando, including setting up the drives where the OSes would be installed.

How to install first Knoppix 8.2 and then Debian 9.11.0, on the HDD without changing the Doze MBR? I don't want to get rid of Doze immediately. Could the code:
Code:
grub-install --root-directory=/media/sdXN /dev/sdX s.t. X=Alphabet letter, N=Number
help me set up a Grub menu list using the PenDrive Knoppix? Ihave run Debian Set-up and it generates a Menu List, but I have never tested using Knoppix.

The reason why I can't use Debian first is because I don't want to burn a DVD drive with the Live ISO. Also, I don't know much about the new Grub, the specific (loop) code for Debian Live 9.11.0 to boot the OS from its image and practical issues and trouble-shooting. Which brings me to my next question.

Question (2): Which among these files are responsible for the Menu-List?

The files within the boot directory are found by:
Code:
/media/sdb1/boot/syslinux$ ls
balder.img
bootefi.msg
boot.msg
f2
f3
german.kbd
gfxboot.c32
grub.exe
ifcpu64.c32
ldlinux.c32
libcom32.c32
libmenu.c32
libutil.c32
linux
linux64
logo.16
memdisk
memtest
menu.c32
minirt.gz
syslinux.cfg
syslnx32.cfg
syslnx64.cfg
vesa.c32
vesainfo.c32
vesamenu.c32


Of these, the binary ones that are eliminated as probable candidates from being Menu-List files are:
balder.img
bootefi.msg
boot.msg
f2
f3
german.kbd
gfxboot.c32
grub.exe
ifcpu64.c32
ldlinux.c32
libcom32.c32
libmenu.c32
libutil.c32
linux
linux64
logo.16
memdisk
memtest
menu.c32
minirt.gz
vesa.c32
vesainfo.c32
vesamenu.c32

Which leaves these probable candidates being Menu-List:
syslinux.cfg
syslnx32.cfg
syslnx64.cfg

I have only used init 3 code-bit or these three files. This brings me to the third question:

Question (3): How to compose for a full-fledged menu list?

I am also testing and preparing a specific loopback code for Debian 9.11.0 simulatneously, but haven't yet found success.

Any help that could be extended?