It's hard.
Make sure you have a very supportive and comfortable bed. Air beds are not that good - we have camp beds, and mine has a good SIM which is a godsend.
You need a very good, comfortable and supportive chair, mine is a vango - I went for a large seat, high back and arms. I've also got a foot stool.
Don't get cold, so warm pj's, hot water bottle etc. are essential. I am considering taking an electric blanket as even in July/August costal sites can be quite chilly at night.
Be prepared for a trek to showers and toilets, most campsites have push button showers which is a pain - we go to the same campsite each year, purely because they have decent, spacious and unlimited shower time (thanks to the fact they don't have push button showers and the water is hot. They also have a coffee shop with comfy sofas and armchairs which were absolute bliss when camping chairs get too much.
You will walk a lot more than you think, so if that's an issue, be prepared, good trainers will help.
I always make a list of the nearest B&B's just in case I need a night in a decent bed and a soak in the bath. Painkillers. All of them.
I've camped for years, but DH and DD know that sometimes it's not as comfortable for me as it is for them, I manage fine, but we will be upgrading from a tent to a caravan because my back and hips are steadily getting more painful.