Sadly it isn't looking too hot right now. Losing tissue and on the verge of death/dying, but it could just be part of it. I would limit the lighting and flow and double check all your parameters ie Cal,Alk,pH,Nitrate,P04,salinity etc. How is everything else doing in the tank? Anything else look stressed out? Maybe someone could chime in with more info to help.
Goniopora are difficult corals to keep. If you are truly new to corals, that's not a good one to start with. I'd suggest something more hardy, like some soft corals. Toadstool leathers, mushrooms, green star polyps, xenia and the like.
Unfortunately I have no suggestion for saving your goni, as I couldn't keep my own alive.
Goniopora or teapot coral are not easy they from what i have heard enjoy nutrient rich water...DONT GIVE UP get some leather coral (small one) they grow fast) they fill a tank and look nice then work your way into lps corals (they are cool b.c they have tenticals that extend at night for feeding when you get lps corals you in a sense get 2 diffferent corals b.c from day to night they look indistinguishable