Of course it doesn´t have to be camping as such, the majority of Spanish sites have cabins and chalets to rent, so if the camping lifestyle is for you then campsites with bungalows and alternative accommodation might be the thing and no equipment to carry.
Campsites are quite often rural but Spain also has many muncipal sites many within large cities such as Cordoba, these can offer an affordable and different way of seeing the country.
Spain is a vast (compared to the UK) country and there is a huge variety of campsites all across the peninsula. They range from small very rural site surrounded by olive groves to vast commercial enterprises on the coast.
As the south-eastern area boasts over 300 days of sunshine a year campsites make a great base all year round from a week to a winter stay.
I live in Spain and share many of my campsite findings on my http://www.camping-in-spain.blogspot.com blog, join me there, ask questions or share your camping experiences on the this forum.