Need Some Help...on everything

Hey, I'm new to everything about this. I'm 17, and got lucky when my parents hooked me up with a 2009 Malibu. I want do a couple of things to it, but I dont know where to start. I'd like to put some new speakers in it, and I was looking at the "Duraflex" Body Kit.

Im not looking for a lot in the speakers, but I want to take it up a few notches, and body wise, I have no idea if those Duraflex body kits have been used, and/or are dependable.

Another problem is, I really don't know much about installation, cost, speaker type, or anything involved in it. Pardon the inexperience, but I figured this would be a good place to look for help.

I'd love any suggestions on anything for the Malibu, but I also need to know the price, whether its better to do it manually, or get installation, etc..

Thanks a ton,
Crzyguy0125