Welcome to the club! I had an i-music as my first car which is a special edition of the extreme. Amazing first cars!
The usually list of things people do to a 1.2 16v would be to put it on lowering springs, spacers and new alloys. There's not much extra power to get without it getting expensive.
Spitfire1 a member on here has done a fair amount to his with uprated wishbone bushes, coilovers with solid top mounts, induction kit, exhaust, sport cat, and a remap. He's pushing out around 91bhp.
Or do what I did and pop down to halfords and shove on a massive pod filter and laugh every time you put your foot down.
If you were to start seriously modding the 1.2 16v I would sort out those front seat straight away! You'll find that around certain corners the seat seems to eject your body off the seat into either the door or the gear stick.