Not bad for a first time, pretty good if you are over 40, it would land you top 30% in a local road race so you are fitter than average but that isn’t really much to be proud of because obese = average. But to be honest with you, with a 23 minute 5k, the only reason you are fitter than average is because your bmi is lighter than the average obese person. In terms of conditioning, you are average. Which means at your weight it is a mediocre effort and you could get much, much faster if you properly trained for the distance.
Compared to male runners training 5-7x a week in the prime of their life, this time is quite poor and you should aim to be much faster. If you are in your prime and have no lifestyle restrictions such as excessive smoking or drug use then could get sub 20 quite quickly, that should be your next aim. After you start getting under 20 you should aim to knock off a minute at a time as it will get slightly arder until ou reach 17 minutes, in which case you should train to lower our time by 30 seconds u til you reach 15. Once you are sub 15, every few seconds becomes hard to shave off.