Learning Spanish: how many "freebie" recognisable words for German speakers?
From French, Latin, and English, there are lots of words, which are cognates and partial cognates. I am learning Italian (so very close to Spanish) and even though there are many partial cognates, at the very beginning I had very little confidence in my ability to guess them. And my accuracy to guess them wasn't as high as it is now too. I mean, it helps that there are many partial cognates, but it really does take a while for you to get used to how exactly they transfer between languages, in both spelling and pronunciation (not to mention being able to produce them).
So, truth be told, I am a little let down by the fact that I thought Italian would be faster and easier because there are so many partial cognates, but it really still takes a long time to get close to even B1. I've averaged >1 hour per day of study for the last eight months (so 300+, maybe 400 hours) and I can still only cope with graded readers and student material unaided. With native material I still have a low comprehension rate. Sure, there are cognates and partial cognates, but you have to be able to understand them and convert them to meaning at native-level speed, which just doesn't come quickly. Most of the cognates seem to be mid- or lower-frequency words (such as scientific words), so they provide less help at the initial stages of the language learning journey. I mean, it's useful that there are cognates. Just don't have a super high expectation that it means you're gonna learn the language within a few weeks or months.
You studied French & Latin and know English... those three will get you a lot. Not sure about German though. I'm learning French and I studied Spanish in school. I find there are a *lot* of similar words. Not totally the same, they are sometimes spelled somewhat differently and pronounced differently. But many. As well as many with similarities to English.
Not sure about freebies for German, but since you mentioned fluency in English, there are TONS of freebies for English speakers (with slight alterations). It's the main point of the book Madrigal's Magic Key to Spanish. I've only flipped through the books before, but it is often recommended.