Hi Babyamy, I can suggest Tenby in West Wales. It's a lovely little seaside town with a smattering of shops, some nice hotels and cottages and quite a few bars. You're also close to the old market town of Carmarthen, where a new shopping centre has just opened. Unless you're looking for busy and hectic, this place is ideal in the summer months.

Almost forgot to say you can travel there by train as the station is very central.

Brighton ticks all your boxes.

Bournmouth?

what about portsmouth and southsea with the isle of wight not too far away? rail links and ferry links

I would second Davey Brighton is lovely stayed down there myself for four days last year I happened to pick four glorious days and had sun all the way. There are plenty of B & B Hotel's etc to suit most budgets, parking is not great I would say however I stayed in a hotel and they had ticketed parking in the street for £4 per day, which I thought was a bargain. There is plenty to do open top bus round around Brighton giving you a potted history lesson, the pier is a must (although they freak me out as I can see through the wooden bits so cn only walk so far ). The sea life centre, pubs restaurants - plenty to suit all ages.