The 5-1 system is a system with 5 attackers(2 OH, 2MB, 1 OP)and 1 permanent setter. During the rally the players will move to their playing position which are for setter and opposite the roght side of the court; the middle in front row will be in the middle, the one in backrow will be substituted by a libero and will be on the left, the OHs will be on the left in the front row and in the middle in the back row. Here is a vid to learn the rotations https://youtu.be/rBvw_He47Z8?si=qY0rE05JhQ6whLfz
Another thing to work towords is also arm swing speed which requires coordination as full muscle chain has to be involved and some specific exercise to develop explosiveness but iΕ₯s not hard to find them
I dont know if you mean this but the block can touch the ball and it does not count as a "first touch" so the blocker could touch it inmediately again without doing a double