Should I upgrade to a 7D from the 60D that I have at the moment

I suggest you keep the 60D and look into some photography courses, as you mention in your question.

Yes, it's true that the 7D can shoot faster in succession.  But by shooting on auto/p-mode you'll probably still get the same results.  I don't know what animals you're shooting, but if they're not sitting perfectly still then try going into Tv mode and set a shutter speed around 1/200 or faster.

For your Northern Lights shots, try Av mode with the smallest f-stop number your lens has (I'm guessing f/3.5) and fix the ISO at 100.  Then the camera will decide how long to keep the shutter open.  If the shutter is open for too long then you'll start to see star trails.  If that happens then you have to start bumping up your ISO.

Good luck!

Taking a class is a really good idea.  Learning how to operate your equipment is more important than buying new gadgets. 

The 7D is not so much of an upgrade from the 60D in terms of photo quality and noise.  It has more access to manual features, which make changing settings less of a pain.  It also has some weather sealing to keep out moisture.  The best solution for noise is to upgrade to a full frame sensor.  You can get a used 5D Mark II for about the same price as the 7D or a 5D mark I for about half the price. The link is for KEH.com for a look at prices.  Another solution is to invest in fast glass (preferably prime lenses).  It's not cheap, but it will allow you to lower ISO and still keep up your shutter speed.

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