Welcome to the Club, your going to get lots of advice here for a 2k ssei
This is an easy car to mod but the $$$ can add up quick.
Cold air intake is one of the first mods to make. Some (me included) only have a drop in k&n and gutted air box. There is a resonator tube that mellows the supercharger and restricts air flow. More air more power, simple.
Next would be a pulley swap, get a hub kit so you can change pulley sizes as you mod. This will give you more boost which in turn will make more power, cheap too $129 online.
With all that extra air you need to open the exhaust, headers or ported manifolds combined with a high flow cat, pricey but worth the money.
Now your ready for high ratio rockers and a custom burn PCM, spendy as well.
At any point you can add the LSD and any suspension work you want?
Look for Rogues Mods as well as SilverBullet, TaylorD and caminator2k, and have modding your ride