You should always do finger support to strengthen your fingers. The left-handed setter is a great advantage, and it is more suitable to be a setter than the right-handed player. Left-handed players can handle the second ball more easily and are more concealed. You can go to a bookstore or buy CDs online, but the most important thing is to have the guidance of an excellent setter. The sports life of an excellent setter can reach 30 years old. If you want to be an excellent setter, you need to use your head and practice hard. There is no shortcut.
I hope it helps you.