You aren't the only person that is thinking about moving to Spain. A lot of people have done it before you. Those people had the same questions as you. So why shouldn't you ask them what answers they found. Or maybe you can help other people find their answers. That's why there are a lot of online places to connect you to other people who can help you figure out what you should or shouldn't do. 

Group (Link)Description
British expatsForum for British people that have moved or are going to move to Spain.
ExpatforumThis forum connects people from all over the world we have decided to move to Spain or are still considering moving to Spain
Expat ExchangeThis forum gives you advice, information and expat connections about a life in Spain. The platform is also full of tips and experiences to make your moving experience easier.
Expat: Spain forumThis forum answers your questions about living in Spain. It also connects you with other expats who can give you advice.
Expat focusThis forum is for everyone who is moving or living in Spain. It helps you with the practical questions you have about moving. But you can also find some properties that are for sale or rent.
InternationsThis forum connects you with British expats all over Spain. It includes people who have al ready moved to Spain but also people that are thinking about moving to Spain. That way you connect with like minded people that can give you advice when needed.
British expat forum
This forum gives you the chance to ask other Brits in Spain for advice on all matters regarding live in Spain. Share your experiences and questions. Who knows maybe you can help other Brits too.
Spain made simpleThis site gives you an honest opinion of a life in Spain. It's written by a woman that lives in Spain herself but also works there. She makes you think about important choices you have to make before moving abroad. But she also shares some great insights