i didn't know I needed a test kit

what kind of test kit should I get?
and it has 1.26% copper sulfate
and I hope it is ich that my naso has, as it does look like its growing out of his face and appears to be getting somewhat smaller in the last day or so, he has been in a qt for only a few days
the guy at the fish store told me that copperpower was really good and it would fix my fish in a week.
and it was not the most expensive stuff, in fact it was the lower on the price than most others he sells