2012 Civic won't start. Says "Check Brakes". Don't know what caused this or how I can fix it.

Solved: Battery and Starter problem.

TL;DR: 2012 Civic won't start. Brakes are hard. Nothing noticeable engine-side.

I have a 2012 Honda Civic. Tonight, I was getting hungry, so I stepped outside into my car and thought I was gonna go for a 5-mile drive for some fast-food.

I felt awkward putting my key into the ignition, and I didn't successfully start the car. I thought just to try again, but now it was telling me to check the brakes. I was stepping on the pedal and it was okay, I thought nothing of it. The lights worked and everything seemed fine, but the car still wouldn't start.

My brother and I checked out the car to see if there was something clear we could identity. Neither of us are experienced mechanics, but we wanted to see if there was something obvious even we couldn't miss. I then decided to try to start the car again, and I noticed, as I put my foot on the brake pedal, that it was hard to push in. I was able to push it in further to turn on the brake light, but the car still won't start.

I've never had any work done on the car, and it has roughly 25k on it. Not sure what the problem is exactly, but that's all I know about it. Anything anyone might be able to say to lend some insight would help a great deal.