izzet can be a what they call a tier 2 deck. Generally cheaper and not as effective as the top decks but built properly can give them a run for their money. They're generally "meta" decks as well, meaning they can be built to beat popular decks at a given time, but generally aren't great by themselves. That being said, you could use some general deck building tips.
To get ready for an FNM test run you need to try the following.
Izzet is generally going to play like a control/midrange deck. They're going to play few creatures, and try to protect them to win, or play alternate win conditions like burn and try to control the board. You need to decide if you're going to keep the white. Most RUW decks (red blue white, american) play like control decks and play just a few win conditions then protect those win conditions. There is a midrange version you can play too.
Lands - more of them, better ones. If you don't want to invest in the check lands (sulfur falls, clifftop retreat, glacial fortress), you should at least try to invest in the shock lands, they'll be standard leagal for the next year. Hallowed Fountain, Sacred Foundry, Steam Vents, also you need more, a control/midrange deck will run 24 lands minimum, usually 25-ish, depending. Gates can be used, but they hurt your tempo. See the following example.
land drops with check lands, and available mana.
Turn 1:shock land, 1 available (possible 2 damage if needed to play untapped)
Turn 2:check land, 2 available
Turn 3:check land, 3 available
turn 4:basic island, 4 available
You could have cast 10 mana worth of spells assuming you had a 1 drop and spells to cast on subsequent turns.
Now with gates.
Turn 1: Shock land, 1 available
Turn 2: Gate, 1 available (gate comes into play tapped)
Turn 3: Gate, 2 available (gate comes into play tapped)
Turn 4: Basic Island, 4 available.
You could have only cast 8 mana worth of spells, if your opponent cast a farseak or ramped with an elf, your down 2-4 mana depending on their line of play. A very bad position for a control deck to be in.
Spells - are you control or burn? are you control or midrange? Control decks use board wipes to help stabilize and keep your opponents threats of the board, mizzium mortars, supreme verdict, ratchet bomb, bonfire of the damned, Cyclonic Rift. You also need to be able to draw, Think Twice, Divination, Auger of Bolas,Azorius Charm, Sphinx's Revelation (bread and butter for a lot of control decks), you need spot removal too, that's instant or provides additional effects or both, Izzet Charm, Azorius Charm, Searing Spear, Pillar of Flame, Detention Sphere, Also Turn/Burn is a must in any deck with red and blue. You need at least a couple counter spells like dissipateand syncopate, they have an exile component that is important currently. Negateis okay, but I would only run one of those, Essence Scatter can be a 1 of as well in addition to the dissipate and syncopate.
Creatures - control decks play 0-10 creatures where most midrange decks play, 10-20-ish, control decks will try to get the game to a place where they can either play their threat and start beating their opponent, where as midrange decks usually stick multiple threats on the board and attempt to trade up with 2 for 1 spells and effects. Guttersnipe can be good, if built around properly, Nivix Cyclops and Young Pyromancer
Getting down to 75 is a good start, (60 main, 15 side). Obviously as a new player you wont' have access to everything I mentioned, but you can look at the deck lists below learn from what they're trying to do. Right now you're kind of all over the place.
Deck examples
http://sales.starcitygames.com//deckdat
ckID=58170
http://www.channelfireball.com/articles
yromancer/
http://www.mtgtop8.com/archetype?a=262