Depends on so many different factors.
I live alone and could easily manage on less than that..
BUT I don't do anything or go anywhere and live in a cheap part of the country. Although I did include an average for water bill (in Scotland water not privatised here), and what full amount of council tax would be. You didn't include that though so if council tax already accounted for that actually makes it more doable.
I would highly recommend posting a similar thread on money saving expert forum
Do a proper list of your potential income and outgoings for the scenario you're considering known as an SOA - a statement of affairs
So eg
IN
Salary
Child benefit
Tax credits if you get
I'm on benefits so different
OUT
Rent
Council tax
Gas/electric
Internet/landline phone
Mobile phone
Mobile phone ins
Tv licence
Any insurance costs
Groceries
Any you need to save for infrequent costs - Xmas, birthdays, haircuts, clothes (they WILL need replacing at some point and you certainly need them for your dc, replacing home items as we all need it at times, and frankly you should have some savings if at all possible for emergencies)
TOTAL
Why is the phone bill so high? I'm guessing latest phones at the time? Definitely change the tariff ASAP and as soon as you've paid the devices off switch to sim only and DON'T buy new phones until those ones are done and when they are you don't have to get the latest models. And I speak as an iPhone addict! But I never get the latest model. I'm on my 3rd and it's an iPhone 7 bought end of last year. And shop around for the sim only deal. I'm with Tesco mobile who do sim only deals from £7.50 a month. I pay £26 approx for device and airtime. BUT don't skimp on ins good ins is worth its weight in gold! And don't pay for SIM cards, the vast majority of companies are happy to give them free to new customers when you switch to them but it's not absolutely necessary as you can switch without changing your SIM card.
And you shouldn't be charged if switching after contract is up, providing you're organised and give the right notice. You only owe them money if you're switching before the contract is up as you owe them for the device and to meet the terms of the contract.
www.ofcom.org.uk/phones-telecoms-and-internet/advice-for-consumers/costs-and-billing/switching/switching-mobile-phone-provider
DON'T go on a meter for gas/electric the rates are MUCH higher than for credit meters, what you could possibly do is get a smart meter so it's easy for you to monitor usage.
I'm stuck on a sodding meter thanks to previous tenant and difficulties switching as a result and it's costing me a fortune! As much as £150 a month in the winter! (I was in the middle of sorting when all this kicked off!)
I'm not sure if that's also true for water.
Would help to know roughly where you are too, even county? As rates can vary hugely regionally.
For the things you asked about I'm
Gas/elec £150 in winter bit less in summer
Water - via council tax here £20
WiFi - Plusnet Unltd £18.99 (Inc landline)
Groceries - my costs are high due to mental illness (inc agoraphobia which means can't shop around as much) and disability affects what products I need and can use but if I adjust for what I would be buying if I weren't ill it would be about £40 a week which is approx £175 a month
When I am not housebound and can shop around I've found that:
Home bargains, b&m and Willko were cheaper for cleaning products, paper products (loo roll etc), and toiletries.
SOME of their food lines are cheaper too - but some aren't so be careful
Pound shops - again cheaper for some things but be aware not always, eg branded baked beans can appear cheaper in pound shops but they're much smaller portions so cost per kilo its actually more expensive. And the quality can be questionable eg I stopped buying pens out of pound shops as more often than not half the pack wouldn't work. So a false economy.
Bodycare, semichem and savers are also good for toiletries and I've heard cheap for nappies etc too
Bulk buy non perishables when they're on offer - I've noticed that offers on popular branded products tend to cycle the supermarkets. So
Week 1 on offer in Tesco
Week 2 on offer in ASDA
Week 3 on offer in Morrisons
Week 4 on offer in Sainsburys
And each supermarket has best prices on different items.
So figure out what you like and is cheapest for your household from each supermarket near you.
Also check out independent shops, and if there's a market happens near you that too, supermarkets undercut them initially to gain our loyalty and then once they had that prices crept up. Now they are often not only cheaper but better quality/fresher products. So check out local greengrocers, Bakeries, fishmongers, butchers...