OK, you are good... Just make sure that your BIOS is set to allow UEFI boot also. I just went through this with a brand new laptop install over Win 10. And because of the maker I had to go change another setting to allow the USB to boot aside from the BIOS.
But keep in mind your Linux ISO absolutely has to be bootable from the stick with “either option”, and this is indeed an option available. If not then it will be picky no matter what you have your BIOS set as.
The install will do the dual boot for you, the new 20.x install requires you to go into “other” that the 18.3 and the 19.x did not reguire. And then it will be self explanatory.
You need to get the newest version. It is UEFI and 64 bit only... So many want to go for “light” or “something I can play with because I am an IT tech”. No, just load the right one to begin with and you are good to go. It just works and you do not have to know a thing about tech. :)
Thanks for the help. I got cinnamon 20 installed and the only thing is that it defaults to windows if I don’t hit the escape key on boot up. I can live with that.