It should give you the needed information on how to add the additional node to your set-up. As far as making a Active/Active/Passive SQL Cluster IDK... I have not heard of this and do not know if it would be supported or possible.

When we used to do performance clusters you had to have four systems for Failover. Each active node needed a passive node. You may want to look at building a Three Node Hyper-V system with the VM's hosting your SQL server instances running across two of the thee possible nodes.