For a first go at it thats not a bad time at all! I've only ever done 2 pursuit's in my life. I did a 4 km a couple years ago because it was part of an omnium (5:05 I think) and a 3km last winter as a joke against another sprinter. (high 3 min)
Keep workin at it and see what you can get down too.
I'm a beginner too, and my first (and only, so far) kilo was 1:23, which I was told was "pretty good" for a first effort. In fact, a friend who is a former keirin pro said 1:23 is the same as his first kilo.