My favorite bands are (In order) Blink 182, Nirvana, Radio Head, & Sum 41. So you can kind of tell my favorite type of rock is punk rock
Wait, how are we supposed to know that?

Rubah is right. DO NOT buy an instrument at wal-mart. If you want the worst of the worst.. pure trash when it comes to instruments, then buy from walmart. Don't buy one of those ridiculous starter kits either. Those things are smurfing trash. Buy an instrument, and an amp, and a cable, by themselves. You are going to want a semi decent instrument. Maybe not a top of the line instrument, but a decent one. A bad guitar will go out of tune if you sneeze on it. The sound quality you're going to get is simply monstrous, and it's going to be very difficult to play. How an instrument feels, in my opinion, is the single most important factor when selecting an instrument.

Can you borrow one of your friends guitars for a little bit? That is what I recommend you do first.

Dude, take lessons. You are going to suck for a long time regardless, but if you don't take lessons, you'll probably suck forever. I cannot emphasize the importance of taking lessons for at least a year or two.

Does your band have a bass player and a drummer? You aren't considering having a band with 5 guitarists, are you?

What kind of music do you want to play? If you want to play the music that you described you shouldn't get an acoustic guitar. That comes later, when and if you get into folk and/or classical. (Although you don't necessarily need an acoustic for that)