Esperanto: English or Spanish

When learning a foreign language (in my case, English, Polish, Spanish and a bit Hungarian, being native in German), I've tried to avoid any other language as much as possible.

To me, the act of translating always felt like an interruption of my learning process.

So, I'd recommend not to translate at all, but to associate Esperanto sentences with situations. I know from my own experience that it's possible and quite successful.

To become fluent in whatever language, you have to drop the translation process anyway. In a conversation, you simply don't have enough time to translate to your native language, prepare your reply and translate that back to the foreign language.

With your background of English, Spanish and German you'll probably be able to guess the meaning of many Esperanto sentences even without a formal education.

According to this statistician Esperanto looks closer to Spanish, and the Automated Similarity Judgement Program also seems to suggest it is closest to Italian, which would make it more similar to Spanish.

That being said, "similarity" is maybe different in an artificial language from a "relation" in a natural language. What I mean is, while there may be more words with similar roots, because it's an artificial language it might not be as consistent in following similar rules like German and English because the language didn't grow naturally from another. Also, Esperanto is famous for being easy because of it's grammar- there are no word genders, no conjugation, perfectly phonetic, no random rule exceptions, easy consistent vocabulary. For these reasons, I would just learn it translating to whichever you feel more comfortable with or whichever you can find more learning materials in.