I saw you also posted where you are moving to - an area which in the past has seen quite a few Brits moving there successfully. The most important thing at this time is if you do need to work - do you speak Spanish and what are your skills. Someone who is a well qualified car mechanic who speaks fluent spanish may well be able to find relevant work but it is much tougher now. Spains unemployment is still high and they tend to protect their own first (family, friends, neighbours, other Spanish). the days when you could walk into a job speaking English are gone. Before there were lots of foreigners requiring services - hairdressing, real estate, plumbers and there were more “successful” English businesses willing to employ English people but that has changed.
The other simple option is if you already earn money using the Internet of as an author etc and can be geographically mobile then you should be ok.
I am sure schools and healthcare will not disappoint if you are able to set yourself up financially first.
You probably don’t want to hear it but even though it is sunnier here life canbe even tougher than back in the uk until you get established.
Best of luck