UC is £92pw in your pocket and your rent gets covered separately.
Min wage is £343pw, rent is going to be at least £100pw, travel to work is going to cost at least £50pw, leaving you with £193.
So you are £101pw better off for working. Except you’ve lost your entitlement to free school meals, prescriptions and dentistry, council tax support, warm home discount scheme, cold weather payments, and various other discounts available to UC claimants. But the big issue is going to be childcare - it’s going to cost around £100pw per child, more during the holidays.
As a single person you’re a few hundred quid per month better off working. With one child you break even - and most won’t bother if they aren’t going to be better off for making the effort. Two or more kids and there’s no point working.