first off i just put a new fuel filter, fuel pump, and new bosch +4 plugs in.....my gas mileage has decreased from 27mpg to bout 22mpg.......any suggestions??
and then sometimes the ignition just clicks when trying to start the van....like over and over till it finally starts up....no idea what that could be! help is much appriciated!

Get rid of those multiple electrode plugs. People always seem to have problems with them. Get single electrode platinum plugs if you want, but I got Champion copper plugs (the most basic plug) and mine runs fine.
As far as the starter, certainly sounds like the starter solenoid. However, you may have to replace the whole starter assembly (I have the same problem with my truck).

My '95 caravan has this exact same problem

The four electrode spark plugs would be the first thing I would get rid of.The extra electrodes mask the flame front.Use a single electrode plug for the best efficiency.
The starting problem could be corrosion on the wires going to the starter from the battery.The clicking you hear is the starter relay (solenoid) rapidly closing and opening the contacts due to low power at the relay.A weak battery can also cause this but usually the engine won't start because of the low available cranking power.

ok so the clicking was the starter BENDEX. had to replace the whole starter ($95 with a $40 core charge) from advance auto. looking at new plugs now....

I get good hwy mileage on my Bosch +2 Platinums. 25.8 mpg with A/C on my 3.3L 99 Sport.