How to Dual-Boot 2nd OS?

This is more or less a project, seeing if I CAN do this successfully without messing up my Windows OS. I have 2 hard drives (both same 2 TB capacity); one is my main Windows 10 OS system, the other was/will-be intended for system-image/macrium-reflect backups in-case my main OS drive bites the dust. I want to try my hand at installing linux on the 2nd drive and dual-booting windows and linux without problems

I have my BIOS set to run on UFEI instead of Legacy (used the mbr2gpt tool on my Win10 OS drive), and from what my system info tells me, I can't run secure boot at all on either drive.

How would I go about doing this right. And if I decide that dual-booting isn't worth it and I delete linux from my 2nd hard drive, how would I fix my windows bootloader (if it needs fixing at all). The intended linux build is android-x86

. You must be in Windows for this to work.
The second ox must have a security code or whatever it's called for the new UEFI's for it to work, too.
I can't remember but you may need to turn off Secure Boot. (Do a web search on that one for Secure Boot and secondary os's.)
You must create a new parttition or have another ssd/hdd with more than enough space for the new os.
Now once that's all been checked and done, install the other os.
Then update it, configure it, restart into it for everything to take.
Then exit that os and go back into Windows to double check everything is fine.
Boot os's listed on the startup screen for you to choose which os to start,
Once that's all done you're all set. .

Simple way is run it as a virtual pc with free virtual box no messing or formatting drives or boot records

Agreed with everyone else. Just run it in Virtual Box or some oth Virtualization program to test it out first.
Then decide on if you want to leave it how it is or if you want to install it as previously mentioned.

I used to dual or triple (or more) boot, and had done so for many years. With the older hardware, I preferred it to virtual drives. I’ve recently upgraded all of my equipment and converted to virtual drives for everything. My biggest complaint with duel booting was having shut down everything on the current drive, reboot and then wait for everything to start up on the other drive. Even so, on my older hardware dual booting was much preferable to virtual drives. Now I have a 6 core machine with 16 GB of memory running up to 4 virtual machines through Hyper-V, and I see little or no difference in performance between live and virtual.

When I used to dual boot, my preferred method was to install each OS on a separate physical drive. When I was installing an OS, I would disconnect all other drives. When all drives were set up, I would set my primary drive in the bios. I would boot into my latest version of Windows and install EasyBCD, which is a boot manager. Then I would reconnect all drives. Then I set up each drive in EasyBCD. Usually everything worked as expected. After the first couple of times, it seemed to pretty easy.

EasyBCD only runs on a windows OS, but you can use it to boot Windows, Linux, VHD off bare metal and maybe a few other things. It does say that some features are not available with UEFI.