great choice on a starter coral, shrooms are great and are very low maintenance. when i get individual shrooms, i usually unplus all my filters/powerheads for a few hours after acclimating, and place it in a spot that i want it, this way its not disturbed by lots of motion. they will grab hold of the substrate after that and will be attatched. they wont sting fish, but can sting corals that are in close proximity to them. they grow large and fast, but defiantely look cool. keep your eyes out for ricordea shrooms, these have to be my all time faves!
good luck
jon