Whats the Easiest coral to maintain?
 

im starting a 2.5 gal salt aquarium and am wondering what i should put in it just to get used to salt water and start easing my way into salt.

First I wouldnt put anything in a 2.5 gal. But polpys are the easiest I think to take care of.

green star polyps, mushrooms, ricordia, and zoa.

They will all be the same difficulty.

I'd go with some expensive ricordia Yuma since you can easily cut one into 8 pieces and watch them all grow out. In a 2g tank you'd have low flow and low light, all conducive to the healing process of the shroom. In about 3 months you'll have a field of rics. They then tend to reproduce like crazy when several of them are clustered together.