I was changing my front disk brakes. Is it supposed to look like a huge empty cavity?

And are my pads supposed to be pressed hard against the rotors?

 

1st pic is the caliper bolted on the bottom? doesn't look like it's quite in place.

and yes...the pads will be firm against the rotor.

 

The rusty cavity you see is the caliper piston that pushes on the brake pads.Its hollow simply because it doesnt need to be solid to do its job.Being hollow reduces its weight and minimizes surface contact with the pad,reducing heat transfer.
You have to push the piston back into the caliper,install the new pads,then bolt the caliper back into postion.Once tightened up,push the brake pedal a few times to extend the pistons and reset the system.The pads will always rub against the rotors,but you should be able to spin the rotors without much resistance.If the rotors binds,the slide pins on the caliper may be dry/seized.You can wire brush and lube them up by removing the caliper from its mount.Just dont hang the caliper from the brake hose.Hang it from a coat hanger or set it on top of the rotor while you clean and grease the 2 pins.

 

your rotors are looking kinda sketchy too, id remove them and have them milled.

 

PLEASE listen to paradox. You DON"T want your rotors to get any lower.

 

I believe you speak from experience.

Now I have to dig that picture up from that "Slotted or Cross-drilled" tragedy of a post...



Lol, I can't help but laugh at how bad that really is man.

 

^^ holy stink!

never seen rotors get that bad before. lol

 

That's Jay's. I think that's why he's urging to not let them get worse. Lol.

 

I shall forever be the icon on WHY to change rotors every so often
That was on my 323, not my RX7, btw