Okay, I am a noob to bikes. I just recently got a bike but am now just fixing it up. I'm pretty sure it's 9/16" and my question is... Can I change my pedals without a pedal wrench? I have other tools.

What other tools?

just use a regular crescent wrench that'll fit on the little wrenchy part, remember one of the pedals is reverse threaded

If you have a 15mm open end wrench, you're good to go.

Like different size wrenches, pliers, and different screw drivers. Basic things.

Sweet. Thanks. I just didn't feel like buying a pedal wrench if I already have some regular ones.

Some pedals also have an hex hole on the end of the screw part.

im sure somebody should yell at me for this but i dont even tighten the pedal nut down with a tool sometimes and just tightest i can with my fingers because if i'm not mistaken, the direction of rotation is designed to be opposite of loosen so = tighten, meaning it'll get tighter and tighter as you ride.
do make sure the threads on both the pedal and the cranks are well greased (Park Polylub should be enough)
and when you can, ride it to your lbs or a car shop, they'd be happy to freely lend you a 15mm open wrench or even a pedal wrench just to be nice.

If you DO use a crescent wrench, tighten into the jaw, not from the jaw. An open end 9/16" will work.