mdadm is the tool you can use to create and manage software RAIDs on Linux. You can also manage them with Cockpit.
If you do go with mdadm, my advice is create a partition on each drive that is slightly smaller than the drive itself, and use that as the device in mdadm. That way if you need to replace a drive, and the new one is a few MBs/GBs smaller, you’ll still be able to use it.