the DR30's use the FJ20 engine dont they?
i'm not 100% sure myself.. but i think thats the case..
in regards to modding it, if you are 16/17, you would be on your l/p plates, so i would leave the car as standard to begin with.
maybe rims, and making it look tidy, but powerwise id say it would be more than plenty.
my first car was a 51kw 89 ford laser sedan.. it was a great little car to learn in.
almost everybody starts off with a little bunky, so its nothing to be worried or ashamed about.
once you have had it for a year or two, and if you still want to keep it, then you can look into modifying it more to gain power, etc..
until then have a read and a chat and enjoy SAU.