I'm not native, but I have been living and working in Austria for the past 9 months or so. That's pretty accurate. "Weit" is almost never used to mean "wide" as we commonly use it. It is more in the sense or "far and wide". "Fern" denotes something being at a much greater distance than just "weit", and it also is used in the sense that something is out of reach. There's not too clear cut of a line between the two words, and there are some instances in which they can be used interchangeably, but there is a slight difference. It's kind of a difficult difference to explain, but as you study more, and see the two words used more in different situations, you should be able to catch on more the the exact meaning.
Someone once said, in this forum, that they should be given the meaning of the words before being asked to write the translation but if you know all the German words that do NOT belong in the German translation, I have learned that the last word that is left over must be the correct word. This way of learning is called "THE PROCESS OF ELIMINATION!" I can't think of any better way of learning new words and adding to your vocabulary and with Duolingo this must be the ONLY way of teaching new words! Just one other thing if you get it wrong, then Duolingo will let you know and in time, you will gradually learn the meaning of new words. This is what I found out.