Actually no, there is another difference between 'this lion' an 'this is a lion'. 'это' means 'this is' or 'this' if your noun is neutral. Since lion is masculine in Russian, you need to use another form 'этот'. ('эта' for female nouns)
So to sum up:
'this is a lion' --> 'это лев' or 'это - лев' (no idea about that one^^) 'this lion' --> 'этот лев'
You have to be patient with Duolingo. Remember that it's a free service and the people who made the course are volunteers too. Also, this Russian course is still in beta which means it's getting improved when users like us report errors. Just hit the "Report error" button on the left side and choose the box that suits the bug.
If it's essentially a subject of a sentence ("What is it?" - Что это?, or "It is..." - Это ..."), then it will be... "it is". But then it can only be Это. You can also attach it to a noun to indicate "this" or "these", but then it will decline based on the gender, number and case of things it's attached to.
Are you talking about a physical Cyrillic keyboard?
If not, in Windows 10 there are three virtual Russian Cyrillic keyboards: Russian Typewriter, Russian Mnemonic and Russian touch keyboard. (There are more Cyrillic keyboards in other languages)
On the Russian Mnemonic keyboard, the - is right where the - is on a standard English keyboard. That's the only one I have loaded, but the preview imagine in Control Panel/languages/Russian/input Device/add input device has the - for the touch keyboard at the same place as the English, and for the typewriter keyboard, the - is where the 2 key is.
No, это медведь и это - медведь mean the same exact thing ("It is a bear" or "That is a bear"). The hyphen is added between two nouns or pronouns in the nominative to indicate that one thing is the other thing without combining the two into one.
"There is a bear", depending on the context, would be just "Там медведь" or "там и есть медведь".
"Это" has multiple roles.
It can be a pronoun, like in "I like this/it" (мне это нравится).
It can be a particle meaning "it is" or "this is" or "that is", etc., like in the example phrase here. That's how it is used when there's a dash after it.
One thing those two uses share is that "это" does not change form, no matter if whatever you're talking about is plural, singular, masculine, feminine, or neuter.
When saying "this bear", though, we're need not a pronoun or a particle, but determiner. And that determiner needs to agree with the noun it modifies. Not only that, it is declined! In that case, это is used only for neuter words. Given that медведь is a masculine, you'd need "этот медведь" instead.