Question SSD secondary to which port, dual M.2 adapter, M.2 to SATA, PCIe 2.0 x 1 or USB 3.0?

Sep 12, 2019
Hi all, question, I just upgrade my SSD drive and my most my meet my motherboard only has one m.2 type 3 port that's for the new SSD drive.
I have my old SSD drive that I want to use as a second Drive, problem is my motherboard only has one PCIe 2. O x1 slot left because the PCIe 3. O is for the video card.
Then it has three SATA ports and it has only USB 3.0 ports, so where to put the backup SSD drive?
I was trying to see if there is an adapter Voyage would be dual pcie nvme SSD to one M. 2 slot adapter.
I found one that looks like it was set up for RAID, I wonder are there any of these that would work without RAID.
if it's RAID only is that something I should do for this.
I was also trying to find an adapter that would take SSD pcie nvme M.2 connector to SATA and to that I would be able to connect that secondary SSD to a SATA port on the motherboard.
Trying to find one still. So here are my all my options, please let me know what you think and what do you think would be my best option as far as speed wise for that second backup SSD.

SSD drive options
1. Get a dual M. 2 pcie nvme SSD to to one M. 2 slot adapter, can use it without RAID? the find out if you have to use it with RAID. Can you set up raid on this desktop with this motherboard? This equals fastest speeds

2. M. 2 pcie nvme to SATA adapter, this would give second fastest speeds at over 560 Mbps.

3. would be a external USB 3.0 adapter to M.2 pcie nvme SSD adapter which would only give around 400 MB megabytes per second speed Max unless it could be boosted if there is a way to buy a USB 3.1 to 3.2 or Thunderbolt extender adapter card thing

4. Option would be m. 2 SSD PCIe nvme to pcie 2 x 1 adapter which would give max speed of 400-480 megabytes per second each direction (500 MBs spec)

I also have to migrate my my OS from the old SSD to the new one, can I do that with only the two ssds or do I need to get a USB flash drive to do the OS move