Whole garden needs revamp

[WalkingBlind]

I've moved into a council property with a decent sized garden but it's a total mess and I've never had one before. They aren't obliged to do anything but clear rubbish.

We tried cutting the grass and it's so uneven (huge potholes and stones) that it broke the strimmer.

I'm thinking of hiring a landscaper/gardener to put in a new lawn and level off what's there? Is this a very costly thing to do usually?

I'd love my kids to be able to play out there and at the minute it's too dangerous

I don't even know what it would need done to it as I know very little about grass/gardens

It is pretty costly to get someone in - do you know how many sq m you have?
do you have time to do it yourself? It's not all that difficult but does need to be done properly if you want a nice flat lawn. And actually now I have written that it was pretty much the most arduous job I've ever done outside but we turfed a really big area.
When I got quotes for seeding or turfing having someone in was about double the cost of doing it ourselves. A sq m of turf will be around £3.50.