Requirement: Slidey freeride wheels are essential. You'll need the ability to break traction, which is more challenging at lower speeds. I recommend between 63 and 73 mm height. Finding out which wheels are slidey can be challenging just by looking at the dimentions ect, this is somthing worth further research on which wheels in production are good to start out on.
Deal breakers: If the surface of the wheel is not stone ground it will be extra grippy the first few slides, nbd for people who know how to slide but for very very begainers this is a dealbreaker. Aditionally I would not buy wheels used for the first set as it can be hard to identify flaws for begainers. Also with no previous experiance, a starter will have no idea if it's their fault or the wheels fault they can't break traction at lower speeds.
