i have just bought a beta and a beta cove,i have had it for about 2 weeks and his ammonia is at 2.0.i took out about half the water is the ammonia going to go down?

I honestly do not know much about freshwater, but i would recommend doing frequent water changes, and that should lower the ammonia. How much do you feed your betta? Does he eat all the food you give him, or is there alot that is wasted? Try to feed him only what he will eat. Lastly, what are you using to test your ammonia?