I want to run mirrored drive for redundancy raid 1 I think possibly 10
You only need 1 additional disk to run RAID1. You'll need 3 more to run RAID10 (4 total). A RAID5 array only requires 3 disks. This RAID level will give you similar performance to RAID0 with the redundancy of RAID1, and with less overhead than RAID10 which is essentially 0+1. The 3rd disk is a parity drive and is what provides redundancy.
If you can get identical drives great, but this is not a necessity. Disks that share similar characteristics will suffice. Similar characteristics are, (plattered drives) rotational speed, cache size, similar read write performance and interface (SATA I, II, III). For SSD, same generation, same memory specification (speed).
Newer controllers are robust and forgiving for the most part. In both cases, size doesn't matter as long as all the drives are the same or larger than one another. We don't have any information from you. Motherboard, controller, OS or hardware?
With that out of the way, your answer. You will need to back up your data and re-install. There are several reasons for this. While many boards come with utilities that claim EZRAID conversion and set up, you will be better served setting up from scratch.
Creating RAID is basically the same, whether you do it in a legacy option ROM or directly in the BIOS. Choose level, choose member disks, they are marked and metadata is written to them. They are then "conjoined" (for lack of a better word). RAID (all levels) is not failsafe and doesn't mean you shouldn't take precautions to back up and protect your data. I or others here would be happy to provide more help/answers based on the direction you decide to go in.