What is reasonable and what it costs isn't necessarily the same. Also be aware that some rental properties are poorly insulated with crap heating systems, so can cost a lot to heat.
Are you a young adult looking to leave home or something else? Is it just you?
If you can live somewhere you don't need a car so can walk/cycle or use public transport to work and anywhere else you need to get to regularly, that can be a good saving, but it depends on your lifestyle, work requirements, shift patterns etc.
The council tax band will be listed on the advert. Water costs on the water company website.
This seems like a good beginner's guide, but be aware that the utility costs are out of date and will be around double what it says.
www.stlegerhomes.co.uk/moneywise/cost-of-running-your-home/
If you don't watch live TV or use BBC iplayer, you don't need a TV licence.
Then you have to think about your lifestyle expectations, things like clothes and personal grooming, eating and drinking out, including coffee and work lunches, cars and maintaining/financing them, phones and other tech, holidays, nights out etc. This is where you have to be careful to 'cut your cloth' if you don't have a lot of money as the amount that people want to spend on these sorts of things doesn't always fit in with what they'd like to spend, but also varies hugely between people, so you have to see if you can make it work for you within the money you have.
Also need to save for irregular and unexpected expenses like loss of income, Christmas etc.