Hi you dont need to speak spanish to live in Spain.
Look at costa del sol, it is as much english as spanish.
Same in parts of costa blanca.

If you do learn spanish which spanish language. Castellon, Valencian, Basque, Catalan, each has its own language. English, that is all you need.

Sorry linguists, is true. If you make and bring money here, people will speak English for this is sure. If you want to integrate of course learn the language, it is polite and good for business too.