I know I can change how long it takes to lock the phone (ex 5 min). However, my display stays on for that long as well. Can I change it so that my phone doesn't lock for 5 min but the display goes off after say....30 sec (for example)
Auto-lock is the time period before the iPhone locks. Lock and sleep are essentially the same.
Passcode lock is the time period before the passcode is required to unlock the iPhone.
If you have the auto-lock set for 2 minutes and the passcode lock set for 10 minutes, your iPhone will lock after 2 minutes of inactivity. You can unlock it without a passcode until the passcode lock time expires, then a passcode is required.