Skating is fun. It is also hard and so is the ice, so make sure your kid wears a helmet!
You don't even need skates for yourself, you can walk and hold hands to make sure the kid doesn't fall. I've found it easiest to be behind the little skater and hold hands or underneath the arms. This way you see where both of you are going and you can get some speed and teach the kid to glide on the ice and enjoy the speed.
It's also good to allow them to experience the balance and letting them fall down in a controlled way to learn how balance themselves upright and that falling down is frequent and to be taken seriously, but not too.
Skating is physically demanding, so take breaks, it's good carry some favorite juice/soda with you and sit down on the bench and take a break and watch the other skaters and talk about skating and how they are doing it.
But remember, it is supposed to be awesome, so go at the pace and do whatever your kid enjoys - kick snow balls, play ice hockey, glide, fall and have an awesome time.