Karen R. answered 06/11/19
Experienced Tutor, Duke Senior, Specializing in Learning Needs
It shouldn't be too difficult, aside from the regular frustrations that are common when learning a new language!
Regardless of how similar a new language is to languages you already know, or how naturally "good" you are at learning languages, it's normal to find language-learning a little hard from time to time. That's okay!
But given that you know English, that may help you in learning German because English is a Germanic language and still shares 1/3 of its vocabulary roots, and a good portion of its grammar rules with German.
Other languages to try with similar advantages could be Dutch or Swedish. Given your knowledge of Spanish, you could also try Portuguese, French, Italian, or Romanian.
In addition, already being bilingual in two languages (in your case, English and Spanish) can also be helpful because some studies have shown that many people find it easier to learn a new language when one already speaks more than one language.
This might be because the brain is already wired for handling more than one language, so it's supposedly not that hard to simply add another language in the mix compared to adding a second language when the brain is accustomed to working in only one language. Though some people have argued against that theory, in my experience, it's held up for me!
I hope that helped! Good luck learning whichever language you want! Let me know if I can help in any other way.