Quick Question : Help Plz !!

[InFaMoUs JcB]

I'm sorry if this is a dumb question. I dont know alot about cars and im new to the ''car world'' as i am just getting my first car soon. I just wanted to know....

Is it dumb to modify//upgrade a Automatic engine? Because i would like to ''hook up'' my car so it sounds nice and has more HP//Speed. But i've asked all my friends and they say if ima hook up the engine i should get a Manual car....but i dont like to drive manual...so is it dumb to ''hook up'' my automatic car?

I would greatly appreciate anyone who could help me. Thanks alot