M.2 storage devices can be SATA or PCIe. An SATA III M.2 maximum speed is 6GB/s.
You don't have an SATA M.2 device. You need to do a UEFI install of Windows 10 as the drive uses the UEFI firmware to operate.
You can use whichever M.2 socket you want.
1- The M.2 drive has to be the only drive installed.
2 - Go into the bios, under the boot tab there is an option for CSM, make sure it is disabled.
3 - Click on secure boot option below and make sure it is set to other OS, not windows UEFI.
4 - Click on key management and clear secure boot keys.
5 - Insert a USB memory stick with a UEFI bootable iso of Windows 10 on it, USB3 is quicker but USB2 works also. A Windows DVD won’t work unless you’ve created your own UEFI Bootable DVD.
6 - Press F10 to save, exit and reboot.
7 - Windows 10 will now start installing to your NVME drive as it has its own NVME driver built in.
8 - When the PC reboots hit F2 to go back into the BIOS, you will see under boot priority that windows boot manager now lists your NVME drive.
9 - Click on secure boot again but now set it to WIndows UEFI mode. (see #3 above)
10 - Click on key management and install default secure boot keys
11 - Press F10 to save and exit and windows will finish the install. Once you have Windows up and running, shutdown the PC and reconnect your other SATA drives. Do not put anything on SATA port 1 as this is now may be reserved for the NVME drive
The M.2_1 socket shares SATA_1 port when use M.2 SATA mode device. Adjust BIOS settings to use a SATA device.
The M.2_2 socket shares SATA_56 ports when use M.2 PCIE mode device in X4 mode. Adjust BIOS settings to use SATA devices..
I would also recommend installing the Samsung NVME driver at this point to replace the Windows one.
The background here is NVME SSDs do not appear within the BIOS until Windows creates the system partition with the EFI Boot Sector. Your M.2 SSD contains UEFI driver information within the firmware. By disabling the CSM module Windows will read and utilize the M.2-specific UEFI driver.