Before you even decide where abouts in Spain you want to be you need to think SERIOUSLY about finance.....YOUR finance.
It is not easy to get employment even if you speak fluent Spanish, bars etc are closing every day so if your idea is to set up on your own perhaps you need a re think.
If you have a pension or own private income with sufficient capital to survive at least a year or two you will be reasonably ok.
I don't wish to sound defeatist, just PRACTICAL and TRUTHFUL.
I have lived here 8 years and love it, but we are retired and I would hate to be here if I had to find work.
GOOD LUCK whatever you decide but do be careful and plan well.