Learn Turkish: Fil kocaman bir hayvan. - The elephant is a huge animal.

In English, we say "a huge animal". But in Turkish, the indefinite article bir (a/an) usually goes between the adjective and the noun. So the correct order is Adjective + bir + Noun.

Where is the word for "the" in Fil?

Turkish doesn't have a definite article like "the". Because Fil is the subject of the sentence, we understand from the context that it means "The elephant" (or elephants in general) rather than just "An elephant".

Where is the verb "is" in this sentence?

In simple factual sentences in the third person, Turkish often leaves out the "to be" suffix. You could formally write hayvandır at the end, but in everyday language, stopping at hayvan is perfectly complete and means "is an animal".

How would I use the current lesson's word gibi to say something is "huge like an elephant"?

The postposition gibi (like) comes right after the noun it refers to. To say "huge like an elephant," you would build it as Noun + gibi + Adjective, which gives you fil gibi kocaman.