If you are thinking about emigrating to Spain you have to learn Spanish.
Maybe you never thought of learning another language and indeed many people live their whole life without knowing more than their mother tongue. This might be ok for holidays, but not if you consider living in another country.
If you learn Spanish, your acclimatization will be pleasurable instead of frustrating. This is because you can communicate well enough to handle situations as they come up. Maybe you can handle to go shopping or to a restaurant, but what about the administrative procedures, the doctor visits, or the chat with your neighbours?
Without speaking Spanish you might not be able to make local friends. To be honest Spain is much to beautiful, don´t limit your opportunities and live in a English speaking enclave only.
Picture Palacio Real Madrid