Since you already have a fish it will create the ammonia from its waste. I cant remember where nitrites come from but I think its when the benificial bacteria eating the ammonia. Then the bacteria turns the nitrite into nitrate.
You dont need to buy any equipment, all you can really do is test the water to make sure it doesnt get to bad and change the water at the right times(which you'll have to ask someone else for because idk). Also since it is a 2g tank some people will say it cant really cycle anyway, but basically make sure your tank is well established before you put more shrimp/fish in.