What's a decent 2000m time for someone new to distance swimming?

I'm not a newbie to swimming, in fact I've been swimming my entire life, but I haven't had a good swim for about a year now, and I'd like to go back to swimming laps in a pool.

Before my hiatus, I never took the effort to keep track of my distance, looking at the time instead. I did 30 minutes non-stop, then took a break for several minutes, then got back once more.

What distance would be reasonable for me to expect for 2000 metres? I'm 26M btw.