Newbie to modding

there are performance accessories you can add like a induction kit and remap, but to be honest you wont get much more power, I'd say around 20bhp for a rough price of short of £500

I think youd be lucky to get an extra 20 bhp for £500 to be honest. Bit of a waste spending hundreds just for a few extra horses ,literally.

performance wise, you can get an exhaust made specifically for you, fit an induction kit and then get it remapped! you will not see big gains, 15-20 at most but with the remap it will change the responsiveness and could make the power come in earlier so you get more, low down power but you will end up paying a lot for a very little amount of power increase. i would just make it look nice and drive well, like some nice allows, fit decent suspension and lower it about 30mm or so, fit new engine bushes and engine mounts, replace all standard suspension bushes with powerflex bushes, fit new anti-roll bars with a slightly thicker/stiffer one, get the anti-lift kit and bump steer correction from whiteline. these will all make the handle of you car really good, as long as you get some decent and strong alloys with good tires

will a TT swing arm fit the new a3??????