It is related but im my P.O.V. the most urgent issue at moment is the ability to boot via Grub: GRUB/Restore the GRUB Bootloader - Manjaro
The nVidia problem can be solved after that by going into another VC.
Take note that especially with dual-boot setups involving M$, you should set your BIOS time to be in UTC, and do some registry stuff so that M$ also uses UTC.
Otherwise you will keep that problem because Linux in general is using UTC as hardware clock setting, which M$ is doing wrong…