Ga 2

Yes, I agree. I feel this would be most helpful. Thanks!

No, that's not how it works. Yuta actually had a video a while ago about not doing exactly what you did, which is to think that Japanese and English sentences parallel each other exactly. They don't (verbs, and things that behave like verbs, are nearly always at the end of a sentence or clause in Japanese), and が does not correspond to a verb at all, but (since you seem to know German, you'll probably understand what I mean), it marks the subject of a sentence like the nominative case in German. In fact, in the examples Yuta gave, nowhere is there any equivalent of "be", because that equivalent is not usually needed in Japanese. Adjectives like 赤い: "red" and 青い: "blue" actually behave as if they contain the verb "to be" already (so a better translation for them would be "to be red" and "to be blue", and indeed they conjugate in Japanese), and in Yuta's last example (俳優が日本人: "the actor is Japanese") there is simply nothing in the sentence that corresponds to "to be". But that's fine, plenty of languages leave out "to be" when it's clear what is meant. Yuta's example can actually be modified to include an equivalent of "to be" in Japanese. The result is 俳優が日本人だ, with the final だ being what corresponds to "to be" in Japanese (but it's not the only way to say it, it also marks informality, and adding it to the sentence, as far as I know, makes the sentence very masculine-sounding).
As for は, once again it does not correspond to "to be", but instead marks the topic of the sentence. It's a complex thing that cannot be explained fully in the space of a blog comment, but basically it indicates "what one is talking about" and often (but not always) corresponds to a subject in English. But this is actually very complicated, and は and が interact in very non-obvious ways. For instance, Yuta explained in this video how が is used in sentences that mark mild surprise. For instance, one could say 空が青い to indicate that they are surprised that the sky is blue (maybe they just got out of a room without windows and expected it to be raining, but it's not). If, on the other hand, you just want to say that the sky is blue, as a general thing, 空は青い would, I believe, work fine (in informal situations, simply 空、青い would probably work as well, は is often omitted).
Japanese grammar is actually not that complex (actual Japanese usage, on the other hand, is a different beast!), but in order to make sense of it you need to let go of your European preconceptions, in particular the idea that all sentences should have a verb, and that the verb appears after the subject (or at least close to the beginning of a sentence). Japanese doesn't work like that at all, putting the verb as the very last thing in the sentence, when it uses one at all.