Seadown has an enviable position being a two minute walk across a field to the beach. It is primarily a static caravan site but has quite a substantial touring section and is well spaced and very attractive.
Since you are a dog (only joking, but from your pic I assume you have a dog!) you probably love walking - and there is no better place than here for that. The coastal/cliff walks are some of the best in the country. If you wanted, or are up to it, you could leave your car on site and walk as far as West Bay and further towards Chesil Beach.
Charmouth high street itself doesn't seem to have fared well since the by-pass was built. OK, less traffic but no passing trade and businesses seem to have suffered. A couple of pubs there for eating out and enjoying a drink.
Bridport is a market town and Lyme Regis is worth a visit.
If you haven't already done so, you can get a good flavour of the site from their website.
Pitches probably not the cheapest - few in Dorset are.
Me? I go back regularly for all those beautiful coastal walks. The colours are amazing - green clifftops, yellow gorse, blue sea, white wave tops and blue skies. Magic.