Sounds like a good pace for starting roughly 4mph walking and 5mph running. Welcome back just start slow and see how you get on. It's the time not the speed that matters
I rarely use the treadmill but when I do, I do the brisk walk at 6kph and run at 8 to 8.5kph. That is a bit slower slower than when I run outside but I don't feel safe going too fast on the treadmill (and always feel dizzy for a bit when I get off).
That would give you 5k in about 37-38 minutes.
I think you just have to experiment with what suits you. Completing the runs is more important than running fast.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.