Camping

Depends how cheap you want... but we have an air tent and they are so easy to set up https://www.aldi.co.uk/adventuridge-6-man-air-tent/p/712182471902200

2 weeks on a campsite with kids or backpacking?

I know people who have used things like these and they seem comfy enough (although the bright red is pretty awful). If your kids are old enough to have their own room it does have the added bonus of an element of separation.

https://www.argos.co.uk/product/5023628

Nice tents are not cheap, but if you're going cheaper better to go for ones like this where the poles are not enormously long - we had a relatively cheap tent with enormous poles and I think I snapped one the first time putting it up.