The majority of programs and apps will run perfectly well off a HDD. Unless you wan real speed then install to the SSD.
I'm running windows from a 128 SSD and have 3 small(by todays standards) HDDs, all my data (user files) stored on the !st HDD, work files on a second and films on a third, no Raid required as I back up images to external drives for safe keeping.
Raid is used for redundency spreading files across drives to help prevent loss in case of drive failure.
Just add your drive, initial and format is required and maybe split into partitions if required using disk management.