hyperv 2012 R2 create cluster for new server and add host with vm to it

Hi,

i've HV 2012 R2 with existsing VM's on it that it is on a shared storage.

what are my options if i need to create a cluster for that host with the active VM's on it?

can i create the cluster on the exists host and then add another host to the cluster or i need to create cluster from the second host and then add the first host?

what about the shared storage and the active vm's do i need to turned them off when i add the host to the cluster?

what will happened to the shared storage on the main host when i add it to the CSV?(i can map the LUN to both server)

THX