I'm having issues with my new Hi12

I apologize in advance if these questions have been answered or are commonplace.

I bought a new (well, new to me) Hi12 - and I love the formfactor. I like how big it is, and how it has four USB ports when paired with the keyboard. However…

The previous owner had Windows 10 Pro installed on it; I’m trying to figure out how to install Windows 10 Home on it. I have a USB stick already ready to go for install, but I don’t know how to get into the BIOS, if anything.

Also…how can I delete the dual boot option, as well? I don’t have any use for an antiquated version of Android.

Finally…how can I charge this thing? The owner wasn’t able to supply a power cord: yes, I know it takes a MicroUSB cord, but even with it plugged into a power brick (and said brick plugged into the wall) the orange light on the tablet will flash, but sometimes it doesn’t even flash at all. Trying to power it on sometimes is impossible, too.

I appreciate all the help anyone can offer.

Thanks in advance!

Oliver in Toronto