Nitrite Problems

Your tank is cycling. Don't add fish until it's done, or you risk losing them.

Your ammonia should spike, then your nitrite levels, then when they both flatline at 0ppm your tank is finished cycling and you can safely add fish. You have to add bacteria to the tank for that to happen, though.

Many people use feeders to cycle the tank. They eat and poo, eat and poo, therefore increasing the ammonia level. Then that will diminish, and you will get a nitrite spike. When that levels out and both return to 0ppm, your tank is ready.

You can also cycle the tank by adding regular household ammonia. There's a site on the 'net that tells you how, and I'll see if I can find the link for you if you're interested in learning how to go that route. I believe it takes longer than fishy cycling, though.

You can also use a product called Bio-Spira, which usually cycles your tank within 48 hours using live bacteria. I've used it, and I will now use it for the rest of my life whenever I set up a new tank. This stuff is AMAZING.

There's a link to buy it here:

http://fishstoretn.com/bio_spira.html

Did you check your water source? Unless you had a source of ammonia which the bacteria converted to nitrite already (and you just caught it in the middle) that is my only guess.
Your tank can't cycle unless there is a source of ammonia and therefor nitrite. If you use fish, you need to make sure the levels don't get to high. You can do a fishless cycle as suggested (search here at AC too) but ANY time you add more fish, food, or some source of ammonia, you can have a "spike" or mini-cycle. You just don't add some ammonia, wait for it to be gone and then add all the fish you want to. If you're not sure about it, research more. Hope this helps!

NitrIte at 2.0 is deadly, no wiggle room. Try a 50% water change.
If you test "no change" then you need a new test kit. A 2.0 level of nitrIte will kill within hours.

Add 1 tablespoon of aquarium salt per every 5 gallons of water (only add the salt once), it will make the nitrite less toxic for the fish. Also, start changing some water every day to keep the nitrite down (1ppm or less), the tank will still cycle. Try to add some mature filter media or gravel from a trusted source, it will speed things up.

By "mature" filter media or gravel, I mean filter media or gravel that already has the beneficial bacteria on it that your tank needs. Maybe your friend could give you some?