For Littlehampton Kitesurfing you need to head to either Littlehampton East beach or Rustington beach, the latter probably is better as it has a fewer beach and water users.
The water is shallow at low tide and pretty flat so great for beginners and the best time to go is a couple of hours on either side of low tide. Like all West Sussex beaches, you have pebble banks at the high water mark and then flat compact sand providing shallow water although when kitesurfing you need to be a little aware of the wooden groynes.
The beach has plenty of car parking and a cafe and toilets nearby.
Although the shallow water suits beginners you can get a chop that makes it a bit more exciting for the intermediate or advanced kitesurfer.
West Sussex is easy to get to and great car option from London, for details on the Littlehampton area, beaches with the important tide and weather forecast see our Littlehampton guide page.