My first race Criterium

I will be entering my first race soon but wanted to ask a question or 2.
With the Criterium races, say for example a 1 hour race, plus 3 laps.
Well what sort of pace is set at the start for A graders ?
What speed do they sit on for most of the race, and at what point is the
pace put up a notch or two.

Also how do you keep track of your position on the circuit, how do you know
who is the leader.

And what average speed would be had at the end of this race for A graders ?
Thanks for any feedback.
David