is200 for my first car

i’m 16, 17 soon and i’ll be straight to doing my driving test, i’ve wanted a lexus is200 ever since my dad got one, well sold his, i’ve missed it ever since, ive heard it’s one of the least modifiable power wise, in already looking for parts for the outside but obviously i wanna upgrade it as i drive it more and more, would it be pointless modding the engine? shall i focus on more weight loss then trying to get more power out of it?