Well, what's the circuit presented along with the question? What was the exact wording of the question? I'm just guessing, but if they _gave_ you the open-loop gain, they're probably asking, what's the gain of the entire loop?
CMRR is, in laymens' terms, how much a common-mode voltage affects the output. Common-mode voltage is, c'mon. I know this is "basics", but ... Common-mode voltage is the voltage that's applied to both input pins "in common". Like, as if they were strapped directly in parallel.
Slew rate is just, how fast can the output slew, or change. Very much like rise-time.
Yes, but as I've noted, this is the "basics" group - please forgive me if I've been a little harsh with you here. (there _is_ kind of an ambience amongst us old farts that we don't like answering homework questions very much, as you've probably been able to tell.) :-)
Here's a hint that really, really helped me when I was just learning opamps. The opamp (assuming infinite open-loop gain) does whatever it needs to do to its output to make the voltage at the inverting input (by way of the feedback network) equal to the voltage presented at its non-inverting input.