Sue I can recommend this site:- http://www.yorkcaravanpark.com/
We stayed here this year for 2 weeks. The site is newish so hedges are not yet too high, but pitches are huge and are well away from the road - so you sleep well. There is fishing onsite. Facilities are new and spotless. There is a bus stop outside the site entrance with a regular service to and from York - don't take your car into the City. [Seniors bus pass accepted]. From the site you are only a few mins. drive onto the Ring road and same for Shopping Mall & an Asda store. Bread shop 2 mins away.
A lovely well run site, Andrew the owners son [manager] is so helpful & his dog is a real character.
I hope you enjoy your holiday as much as we did.