SATA is a new hdd connection, which is faster. It uses a different cable and power connector, but usually these are supplied with the new motherboard. Each SATA connection takes only 1 device (as distinct from the IDE master/slave), so that each SATA device has its own channel of communication and this avoids the IDE problem of access to one device at a time when you have a 2 devices on the same channel.
If you want to use the SATA connection, you need to buy SATA hdds. But these motherboards still come with IDE connections (check how many) so that you can use you old IDE hdds.
There are many forms of RAID, the most common being RAID 0 and RAID 1. They can be IDE RAID or SATA RAID. You use 2 identical hdds or partitions. For RAID 0, the 2 hdds are treated as one, so that data is written to both which makes the transfer of data faster. For RAID 1, one hdd is the mirror of the other, so that you have identical data on both hdds. The former is for speed, the latter is for security of data.
Whether you want either RAID is a matter for you. If you don't need either, that's not a problem because the hdds can be used independently as usual. You just disable the RAID function.