Translation:The street is long.
긴 길이 길어요.
The long path is long.
(The adjective 길다 means to be long, but the noun 길 is path.)
I think it will sound more natural if road or path is used instead of way.
I think road is much more suitable definition. Yet perhaps path is also road in Korean?
Is there any specific reason why it's 깁니다 instead of 길습니다? Is it because of some rule or is 길다 just special?
It's a rule. All verb stems ending in ㄹ, have their ㄹ removed when followed by the verb ending -(스)ㅂ니다.
놀다 -> 놉니다 밀다 -> 밉니다
street, way, path, road, trail are all acceptable translations.
Without more context there is no way to choose the "best" translation. At this early point in the course, things are bound to be confusing. Realize that the language has a totally different structure from English and the Romance languages, with verbs and descriptive verbs (adjectives) coming at the end of the sentence, prepositions coming after the object of the preposition, particles (post positions) to indicate grammatical function, multiple levels of politeness, and a "nuance" particle (은/는) that can be used pretty much anywhere in a sentence to give it a whole different "flavor." How could it not be confusing?
But it's worth learning. LIke anything, it just takes practice and dedication. Don't sweat the small stuff, like a word having multiple meanings, or the course being less than perfect, or your answer not being accepted when you know it should be.
Check out some of this fellow's Youtube videos and you will get a feel for the language in a hurry. https://www.youtube.com/watch?v=XSPW6cx29bE&index=10&list=PLPCs_Vng3vqCcGT71ZvP5wiWQhDgBzsEp
.. and hard. But, I've been on that mountain top. And I still have that dream...