How does the metal spring hook on to the vacuumn and what does it do? No instructions were included!

They definitely need to include instructions of some kind. It took me 5 minutes of just looking at it to figure it out. It needs to be mounted with the bolt that the pole mounts to going through the center of the spring and putting tension on the pole mount to hold it in an upright position

having trouble getting my 1.5 inch hose to connect what am I missing is there a trick to this?

I wet the end of the connection and push down hard over the connection on the head..

How does this hook to sand filter to vacuum to waste?

I do not have a sand filter, but I hook up vacuum hose to skimmer (take out the basket) then I vacuum

What type of vacuum does this head connect to

I have an 18 x 30 inground pool. I hook a 25 foot vacuum hose to the head with the swivel end. The other end goes in my skimmer after I pull the basket out. You must fill the hose with water and keep the end under the water as you put it through your skimmer. The pool pump and filter will create the suction to vacuum with this head.