ElShalimo is right, plenty of good info there. As he said from Gibraltar to Málaga is better to avoid the coast, much nicer inland but very hilly.
I have to disagree about Granada though, it’s the nicest city in Andalucía! (best tapas too).
Wikiloc is great to find routes.
If you prefer to travel off road there are several MTB-touring routes(read long distance, scenic , mainly off road, non technical paths):
Transandalus is one of them, it crosses the 8 Andalusian provinces in a loop, it’s 2000 km long but you could do a much shorter loop with a bit of planing. It’s been designed to be ridden on MTBs with panniers so shouldn’t be too technical. It’s not marked on the ground but there’s plenty of info on the website (maps,tracks).
Transnevada it’s a new official MTB route. It’s signposted and apparently is very easy to follow. It’s about 500km long, around Sierra Nevada mountain range in Granada province. It’s very hilly, mainly on dirt roads, forest roads and quiet tarmac roads(no technical singletrack). Lots of info in the net but mainly in Spanish.