Annette, you are so very welcome!
The more you read and the more you post, the sooner you'll get the hang of it. We all learn something new all the time.
In your zone there are many Mediterranean plants you could grow. With a south facing garden you'll probably have to choose plants that prefer full sun. I'm not sure what trees are available in Spain, but maybe you could find a book on trees of Spain or trees of the Mediterranean.
I'd like to mention Google. I've heard people say, "Google is your friend". You can go to https://www.google.com/ and search for all kinds of info. I like to search for info on plants. You can also click on 'Images' and often get lots of pictures of what you are looking for. There are many ways to search. For your question about trees I would search like this:
trees + Spain
trees + Mediterranean
Here's what I got when I searched with trees + Mediterranean
The third site down mentions the Carob tree. It's a site from Perdue University so I figure it will have some helpful info. I right clicked on it to open it in a new window. Looks like it would be a large tree.
I often find I can get even more info searching with the botanical names of plants so I searched with the botanical name: Ceratonia siliqua
You could even add + Spain to the search box or click on 'Images' for more pictures.