I’m conversational in Spanish and have visited it a few times, so I’d love to live there. I love the biking culture of the Netherlands. If not Spain, then a place that I could get by with English while I learn the local language.
Other than Spain, I think the Netherlands, Germany, Austria, Switzerland and most of the Scandinavian countries are ones where you could get by with English while you learn the local language. Oh and of course, the UK and Ireland (if you consider those as European). Though because of that, I think its likely you will never really learn the local language because you will have no need to. In most big cities in those countries people will probably talk back to you in English even if you try and speak the local language. But it really depends on what kind of experience you want.